if two numbers differ by 7 and their products is 120, what will be the number?

All_for_one

2 years ago

Let

x and y the numbers

we have

x-y=7 ------> x=7+y -----> equation A

x*y=120 ----> equation B

solve the system

substitute equation A in equation B

(7+y)*y=120

solve for y

y^2+7y-120=0

solve the quadratic equation by graphing

the solutions are

y=8 and y=-15

Find out the value of x

For y=8

x=7+8=15

For y=-15

x=7+(-15)

x=-8

therefore

the numbers are
8 and 15 or -8 and -15