Question

Can someone answer 7-11 for me by 12:00AM

Answer 1

Explanation:

7). x + y = 4 ⇒ y = 4 - x -----> xy = - 96

x(4 - x) = - 96 ⇔ x² - 4x - 96 = 0

D = ( - 4)² - 4(1)(- 96) = 400 = (20)²

`x_(1)` = (- ( - 4) - 20) ÷ 2(1) = - 8

`x_(2)` = ( - ( - 4) + 20) ÷ 2 = 12

Numbers are - 8 and 12

8). It's your turn now. You can do it

9). x² - 5x + 3 = 0

0 <
`x_(1)` < 1

4 <
`x_(2)` < 5

10). - x² + 3x + 1 = 0

-1 <
`x_(1)` < 0

3 <
`x_(2)` < 4

11). x² + 2x - 2 = 0

- 3 <
`x_(1)` < - 2

0 <
`x_(2)` < 1