Answer:
x = -6
Explanation:
5x² + 60x + 180 = 0
5 x 180 = 900
you need 2 numbers that multiplies into 900 and adds into 60. these numbers are 30 and 30. now we can rewrite it
5x² + 30x + 30x + 180 = 0.
split it in half and factorise
5x(x + 6) + 30(x + 6) = 0
this means the brackets are:
(5x + 30)(x + 6) = 0
5x + 30 = 0
5x = -30
x = -6
x + 6 = 0
x = -6
therefore, x = -6.