If 3a2 - (a - 7) + [-4(a2 - 9) + 4a] is equivalent to pa2 + qa + r, then what is the value of 5p + 3q - r?

First, let's simplify the given expression 3a^2 - (a - 7) + [-4(a^2 - 9) + 4a].

This simplifies to 3a^2 - a + 7 - 4a^2 + 36 + 4a.

Combine like terms to get -a^2 + 3a + 43.

So, we have -a^2 + 3a + 43 = pa^2 + qa + r.

Comparing the coefficients, we get:

p = -1, q = 3, and r = 43.

The question asks for the value of 5p + 3q - r.

Substitute the values of p, q, and r into the equation to get:

5(-1) + 3(3) - 43 = -5 + 9 - 43 = -39.