3 oranges & 4 apples=$4.33; 5 oranges & 3 apples = $5.42

[s_mjr99]

Three oranges and Four apples cost $4.33. Five oranges and Three apples costs $5.42. What was the cost of each orange and apple?

 

[arthur ohlsten]

Re: 3 oranges & 4 apples=$4.33? Please help

let o bethe cost of oranges
let a be the cost of apples
eq.1) 3o + 4a = 4.33
eq.2) 5o + 3a = 5.42

Two equations in two unknowns, thus a solution existsd.
A number of ways to solve them and I do not know the method your instructor would like you to use,SUBSTITUTION, MATRIX ALGEBRA, ELIMINATION OF VARIABLES ?

I shall do it by elimination of variables
to eliminate o, multiply first equation by 5 and second by 3. in this way both equations have the same coefficient for o
eq.1) 15o+20a=21.65
eq.2) 15o+9a=16.26

subtract second eq. from the first
11a =5.39
divide both sides by 11
a=$.49 answer

substitute into eq.1 or 2 to obtain o
or multiply eq.1) by 3 and eq.2) by 4 and then subtract one eq. from the other to eliminate a.

Arthur

 

[stapel]

Three oranges and Four apples cost $4.33. Five oranges and Three apples costs $5.42. What was the cost of each orange and apple?

Using the first piece of information, how much would nine oranges and twelve apples cost? (Hint: Multiply.)

Using the second piece of information, how much would twenty oranges and twelve apples cost? (Hint: Multiply.)

Using these two new values, how much would eleven oranges cost? (Hint: Subtract.)

Then how much would one orange cost? (Hint: Divide.)

Then how much would three oranges cost? (Hint: Multiply.)

Then how much would four apples cost? (Hint: Subtract.)

Then how much would one apple cost? (Hint: Divide.)

Eliz.