Word problems not my thing.

Chief343

New member
Joined
Feb 11, 2006
Messages
5
Translate to an equation and solve

I am terrible at word problems these two are giving me a hard time. Please help.
Thankyou

Well here they are :? :

One: Twice the square of a number minus 3 is 47. Find the number.


Two: The product of 2 consecutive even positive integers is 120. Find the integers.

I know sounds easy but looks confusing to me. Thankyou for your time.
 

soroban

Elite Member
Joined
Jan 28, 2005
Messages
5,588
Hello, Chief343!

Designate an variable for an unknown quantity.
Then try to tranlate the English into an equation.

1) Twice the square of a number minus 3 is 47. \(\displaystyle \;\) Find the number.
Let \(\displaystyle x\) = the number.

\(\displaystyle \;\;\underbrace{Twice}\;\underbrace{the\;square\;of\;a\;number}\;\underbrace{minus}\;3\;\underbrace{is}\;47.\)

. . . . \(\displaystyle 2\) . . . . . . \(\displaystyle \times\) . . . . . . \(\displaystyle x^2\) . . . . . . . . . . . . . \(\displaystyle \,-\;\;\;3\;=\;47\)

And there is our equation! \(\displaystyle \;2x^2\,-\,3\;=\;47\)

I assume you can finish it now . . .


2) The product of 2 consecutive even positive integers is 120. \(\displaystyle \;\) Find the integers.
Consecutive even integers "go up by twos" (so do odd integers).

Let \(\displaystyle x\) = first even integer.
Then \(\displaystyle x\,+\,2\) = next even integer.

\(\displaystyle \;\;\underbrace{The\;product\;of\;two\;c.e.p.\;integers}\;\underbrace{is}\;120\)

. . . . . . . . . . . . . . . \(\displaystyle x(x\,+\,2)\) . . . . . . . . . . . . . . \(\displaystyle =\;120\)

And we have our equation: \(\displaystyle \;x(x\,+\,2)\;=\;120\)

\(\displaystyle \;\;\)Go for it!
 

Chief343

New member
Joined
Feb 11, 2006
Messages
5
Tankyou for your help. It was very helpful without it i dont know what i would have done.





Thanx,Chief343
 
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