Solve the following equations by factorizing:

1) x² + 8x + 15 = 0

2) x² - 7x + 12 = 0

3) x² + 2x - 15 = 0

4) x² - 11x + 28 = 0

5) x² - x - 30 = 0

6) x² + 11x - 26 = 0

7) x² - 5x - 24 = 0

8) 14 + x² + 9x = 0

9) 7 + x² - 18x = - 25

10) x² = 17x - 72

1) x² + 8x + 15 = 0

Now what multiples to 15 and adds to 8? 5 and 3, 5x3=15, 5+3=8

so its

(x+5) (x+3) = 0

now solve

x+5=0 x+3 = 0

x = - 5 x = - 3

so the solution is - 5, - 3

4) x² - 11x + 28 = 0

what multiples to 28 and adds to - 11? - 7 and - 4

(x-7) (x-4) = 0

x = 7, 4

10) x² = 17x - 72 (okay ill do 3 of them)

first get numbers on same side where x² is positive

x² - 17x + 72 = 0

what multiples to 72 and adds to - 17? - 9 and - 8

(x-9) (x-8) = 0

x = 9, 8