What is a solution of x2 + 6x = -5?

Answer 1

first, rearrange things in the standard form:
x^2 + 6x + 5 = 0

Now, which two factors of 5 add up to 6?
well, 5 is prime, so the only factors are 1,5
(x+1)(x+5) = 0

why do we always set up the list of factors = 0?
because if the product of two number is zero, one or the other of them must be zero! That means we must have either
x+1 = 0
or
x+5 = 0

So, the solutions are x = -1, -5