Question

1.Simplify ( x +1)(x- 1) + 2x ²

2. Simplify (x + 2)(x - 1) -2(x + 1)
3. If 45 is added to a certain number and the result is divided by 9 ,the quotient is 8. What is the number?

Please help

Answer 1

Explanation:

1)

(x*1) * (x-1) + 2
`x^(2)` =
`x^(2) - 1^(2) + 2x^(2)` =
`3x^(2) - 1`

2)

(x+2) * (x-1) - 2 * (x+1) =
`x^(2) - x + 2x - 2 - (2x + 2) = x^(2) + x - 2 - 2x - 2 = x^(2) - x - 4`

3)

`(x + 45)/(9) = 8\\\\x + 45 = 9 * 8= 72\\x = 72 - 45 = 27`