What is the answer for -a2-19a-88 equals 0?

Answer 1

First multiply both sides by -1 to get rid of all the negative signs:

Thus, a2 + 19a + 88 = 0

then you need to find two factors of 88 whose sum is 19 ie 8 and 11

which gives (a + 8)*(a + 11) = 0

so that a + 8 = 0 or a + 11 = 0

that is, a = -8 or a = -11

Alternatively,

you can solve a2 + 19a + 88 = 0 using the quadratic formula:

a = [-19 ± sqrt(192 - 4*1*88)]/(2*1)

= [-19 ± sqrt(361 - 352)]/2

= [-19 ± sqrt(9)]/2

= [-19 ± 3]/2

= -16/2 or -22/2

= -8 or -11