One number is 8 more than twice another. if their product is 640 , find the answers

There are 2 answers

1. smaller number is -32, bigger number is -20

2. smaller number is 16, bigger number is 40

Step-by-step explanation:

Let x be the smaller number.

x(2x+8)= 640

expand

2x²+8x=640

move 640 to the other side and divide everything by 2

2x²+8x-640=0

x²+4x-320=0

use quadratic formulas to expand then group

x²+20x-16x-320=0

x(x+20)-16(x+20)

(x+20)(x-16)

x=-20

x=16

to find the bigger/smaller numbers, use 2x+8

2*-20+8= -32

2*16+8= 40

-12

Step-by-step explanation:

7 times 5 =35

-3 times 4=-12