Find a so that ax^2 + 15x + 4 + 3x + 5 is the square of a binomial.
Combining liking terms gives us:
ax^2 + 18x + 9
We know that if we factor this out, we get: \((\sqrt{a} + 3)^2\)
Since we know that 6sqrt(a) = 18
We know that sqrt(a) = 3
a = 9.
