For what value of x is angle 1 complementary to angle 2, if m angle 1=5x+4 and m angle 2=7x+2?

Two Angles are Complementary when they add up to 90 degrees (a Right Angle). They don't have to be next to each other, just so long as the total is 90 degrees.

So (5x + 4) + (7x + 2) = 90

12x + 6 = 90

12x = 90 - 6

12x = 84

X = 7