Product= multiplication
x= orange calories
x+15= banana calories
x(x + 15)= 6750
multiply x by parentheses
(x*x) + (x*15)= 6750
multiply in parentheses
x^2 + 15x= 6750
subtract 6750 from both sides
x^2 + 15x - 6750= 0
factor
(x - 75)(x + 90)= 0
set each parentheses equal to 0
x - 75= 0
x= 75
x + 90= 0
x= -90
ANSWER: Since calories are positive in number, the number of calories in an orange are 75.
Hope this helps! :)
