Explanation:
I assume you mean
y = x² + 10x + 11
y = x² + x - 7
well, I subtract equation 2 from equation 1 :
0 = 9x + 18
9x = -18
x = -2
y = x² + x - 7 = (-2)² - 2 - 7 = 4 - 2 - 7 = -5
the solution (the intersection point of both graphs) is the point (-2, -5).