use factoring or the quadratic formula

Question

1.

[3a-12][a+5]=0

2.

x²-18x+80=0

Answer 1

Hello Lorena,

For the first one, it is already factored, so we just need to set each factor equal to zero, and solve,

→ 3a - 12 = 0 or a + 5 = 0

→ 3a = 12 or a = -5

→ a = 4 or a = -5.

For the second one, to factor it,

we want to find two numbers which multiply to 80, but add or subtract to -18,

→ (x - 8)(x - 10) = 0

→ x - 8 = 0 or x - 10 = 0

→ x = 8 or x = 10.

I hope the above helps, and thank you for posting the question with Wyzant.

Michael Ehlers