i think its true
i have to add 20 characters or more so here you go
We have to mutiply factor -2/3 times every agument from the parenthesis.
/+8b
8+6b=-4 /-8
6b=-12 /:6
b=-2 - its the answer
Answers
1) 4
2) 0, 2, -10
3) 0, 5, -2
Step-by-step explanation:
1) x³ - 64 = 0
x³ = 64
x = 4
2) x³(x² + 8x - 20) = 0
x³(x² + 10x - 2x - 20) = 0
x³(x(x + 10) - 2(x + 10)) = 0
x³(x + 10)(x - 2) = 0
x = 0, 2, -10
3) x³ - 3x² - 10x = 0
x(x² - 3x - 10) = 0
x(x² - 5x + 2x - 10) = 0
x(x(x - 5) + 2(x - 5)) = 0
x(x - 5)(x + 2) = 0
x = 0, 5, -2
