Question

Please do the question 8,9​

Answer 1

Answer:

Step-by-step explanation:

9)y⁴ - 9y² - 22

 => y⁴ - 11y² + 2y² - 22

=> y²(y² - 11) + 2(y² - 11)

=> (y² + 2)(y² - 11)

8) Let the number be x.

First it is increased by 15%

=> x + x*15/100 = 1.15x.

Next decreased by 20%,

=> 1.15x - 1.15x*20/100 = 1.15x- 0.23x = 0.98x

Thus the net decrease = x - 0.98x = 0.02x = 2/100 of x = 2%of x.