Mom need help in algebra

0123

New member
Joined
Apr 23, 2009
Messages
1
Hi there, I', new to mathhelp and also to algebra. I don't know where to turn and I found you guys. Please help me. How do you do these problems. I'm taking a refresher course, so I can take some classes in collage. I use to get answer sheet, but today nothing and I'm lost Thanks
1 ) 1. Subtract 16 - (-30) - 42.

2 ) 2. Evaluate b^2 - 3ab when a = 3 and b = -2.

3 ) 3. The lowest temperature recorded in North America is -81.4 degrees F. The highest temperature recorded is 134 degrees F. Find the difference between these two extremes.

4 ) 4. Solve b+3/4 = 5/8.

5 ) 5. Solve 3x - 2 >= 6x + 7

6 ) 6. The sum of two integers is fifteen. Eight times the smaller integer is one less than three times the larger integer. Find the integers.

7 ) 7. A jogger runs a distance at a speed of 8 mph and returns the same distance running at a speed of 6 mph. Find the total distance that the jogger ran if the total time running was 1 hour and 45 minutes.

8 ) 8. Find the area of a circle with a diameter of 9 cm.

9 ) 9. Find the supplement of a 105 degree angle.
10 ) 10. How much more pizza is contained in a pizza with a radius of 10 in. than in one with a radius of 8 in.? Round to the nearest hundredth.

11 ) 11. New carpet is installed in a room measuring 18 ft. by 14 ft. Find the area of the room in square yards. (9ft^2 = 1 yd^2)

12 ) 12. Find the area of a right triangle with a base of 8 m and a height of 2.75 m.

13 ) 13. Find the ordered pair solution of y = 2x+6 that corresponds to x = -3. (1pt)
Max Characters: 400
14 ) 14. Is the line that passes through the points (-3,1) and (2,5) perpendicular to the line that passes though the points (-4,1) and (0,6)?

15 ) 15. Given P(x) = 3x^2 - 2x + 1, evaluate P(2).

16 ) 16. Solve for x and y if 5x+2y = -23 and 2x+y = -10.

17 ) 17. Solve for x and y if 3x - y = 2x +y = 1 and 5x +2y = y +6.

18 ) 18. Simplify [(2ab)^3]^2

19 ) 19. Simplify (3a^2 - 9a) - (-5a^2 + 7a - 6)

20 ) 20. Simplify (a+b)^2 + (a-b)^2 (1pt)
 


Hi Mom:

I regret that learning mathematics is not as easy as posting a long list of exercises, followed by receiving a reply. (If only.)

You posted many types of exercises; some are pre-algebra, some are beginning algebra, and some are intermediate algebra.

If you were to enroll in these classes at a community college, it would take a few months to teach you how to do these exercises. We simply cannot compress 16 weeks of instruction into a single response. (Well, I'm sure that there are several people who "could", but I doubt anybody will. If I tried, I would be up all night typing, for the next two nights!)

I'm going to give you a link to a site for beginning algebra; it covers many topics with lots of examples, and it also has links to other sites. You can always use Google, too.

CLICK HERE to go to the Purplemath web site

Once you're able to make a start on an exercise, then feel free to post specific questions here, if you get stuck.

I have some time to make a few quick comments on your posted exercises. Please, stand by …

 
1 ) 1. Subtract 16 - (-30) - 42.

Subtracting a negative number is the same as adding its opposite.

EG:

5 - (-10) = 5 + 10

17 - (-4/5) = 17 + 4/5

-81 - (-81) = -81 + 81

18 - (-40) - 52 = 18 + 40 - 52


2 ) 2. Evaluate b^2 - 3ab when a = 3 and b = -2.

"Evaluate" an expression means to find the number that it represents.

To do this, you substitute Real numbers for all of the symbols in the expression, followed by doing the arithmetic.

EG:

Evaluate b^2 - 4ac when a = 1, b = 2, and c = 3.

Make the substitutions

(2)^2 - 4(1)(3)

Do the arithmetic

4 - 12 = -8


3 ) 3. The lowest temperature recorded in North America is -81.4 degrees F. The highest temperature recorded is 134 degrees F. Find the difference between these two extremes.

To find the difference between two numbers, subtract the smaller from the larger.

134 - (-81.4) = 134 + 81.4 = ?


8 ) 8. Find the area of a circle with a diameter of 9 cm.

There are formulas for calculating the area of a circle. One formula uses the diameter, but beginners are taught the formula that uses the circle's radius, instead.

The radius is the distance from the center of the circle to any point on the circle (i.e., half the diameter).

Area = Pi * r^2

Pi is a Real number. Its decimal form is about 3.14 .

The radius of this circle is half of 9, which is r = 4.5 .

Substitute these values into the formula.

Area = 3.14 * (4.5)^2

Now, do the arithmetic. The result is the area of the circle in square centimeters.


9 ) 9. Find the supplement of a 105 degree angle.

An angle plus its supplement angle always add up to 180 degrees. What number do you need to add to 105, in order to end up with 180? That number is the measure of the supplement angle (in degrees).

10 ) 10. How much more pizza is contained in a pizza with a radius of 10 in. than in one with a radius of 8 in.? Round to the nearest hundredth.

Calculate the area of each pizza using the formula for the area of a circle above, but use 3.142 for Pi (because we need more decimal places, in order to be able to round the final answer to 2 decimal places). Next, subtract the smaller area from the larger area. Round this difference to two decimal places (nearest hundreth of a square inch)

12 ) 12. Find the area of a right triangle with a base of 8 m and a height of 2.75 m.

Again, there is a formula for the area of a triangle.

Area = (1/2) * base * height

or

A = 1/2 * b * h

You're told that b = 8 and h = 2.75

Make these two substitutions into the formula, followed by doing the arithmetic to evaluate.

Report your answer as square inches.


15 ) 15. Given P(x) = 3x^2 - 2x + 1, evaluate P(2).

P(x) and P(2) are each known as "function notation".

P(2) is a symbol that represents a Real number. To find it, take the given expression for P(x), and substitute x = 2 everywhere you see the symbol x.

3x^2 - 2x + 1

3(2)^2 - 2(2) + 1

Do the arithmetic.


Is this a review sheet that you received from some school's placement-testing office? I mean, are you trying to enroll, and the school is going to test your knowledge on these subjects, in order to determine which math course you should start with?

If your plan is to self-teach yourself this material over the course of several months, to review all of the middle-school and high-school math that you've forgotten, and THEN take the placement test, then that is an okay plan. You will save tuition by self-teaching your own review. There are many resources available to do this.

However, if you're thinking that you want to enroll in school right away, and you want to skip beginning math courses (for whatever reasons), such that your goal right now is to ace the placement exam and start with college-level math courses versus remedial-math courses, then I have a strong suggestion for you: DON'T DO IT!

Learning math is not easy. There are NO shortcuts. To do well in mathematics, you need a strong foundation, and, if you've forgotten most of what you learned in secondary schools, then you currently have no foundation.

The purpose of a placement test is to honestly show you where you need to start.

Trust the result.

Cheers 8-)
 
Top