Question

Use equations to solve the following questions

At a certain store, a football costs $15 more than a basketball. If 3 basketballs and
2 footballs cost a total of $115, find the cost of each ball.

Answer 1

*Let:
x = cost of basketball
y = cost of football;

*since a football costs 15 $ more, you have the first equation:
y = x + 15 $

*next, if you bought 3 basketballs, and 2 footballs which costs 115 $, you will have the second equation: 115 $ = 3x + 2y

*substitute the first equation to the second:
115 $ = 3x + 2(x + 15 $)
115 $ = 3x + 2x + 30$
(put together similar terms and simplify, note the change of signs once you move an expression to the other side)
115 $ - 30 $ = 3x + 2x
85 $ = 5x
(divide both sides by 5 to get the value of x)
85$/5 = 5x/5
17$=x
so, a basketball costs 17$.

*to get the value of y/ or cost of football, substitute value of x to first equation.
y = x + 15 $
y = (17$) + 15 $
y = 32 $
so, a football costs 32$.

*to check the answer, substitute both values to second equation.
115 $ = 3x + 2y
115 $ = 3(17$) + 2(32$)
115 $ = 51$+ 64$
115 $ = 115 $
that means the answer is right.
got from yahoo answer

Answer 2

thankyou!!!