Hey! Your answer for this is
7x^2 + 3x^2 = 10x^2
-2x + 15x = 13x
9 - 4 = 5
Hence, 10x^2 + 13x + 5.
Hope this helps!
I think not sure I think -2 but if I had the whole answer to your question I might know more
X-intercepts
f(x) = 0
4x² - 15x - 4 = 0
4x² - 16x + x - 4 = 0
4x(x - 4) + 1(x - 4) = 0
(x - 4)(4x + 1) = 0 ⇔ x - 4 = 0 or 4x + 1 = 0
x = 4 or 4x = - 1 ⇒ x = - 1/4
Answer: -1/4 and 4.