Question 679660
If angle a is complimentary to angle c then angle a and angle c add up to 90 degrees.

So angle a + angle c = 90
If angle a = 2x-10 and angle c = 4x+40
Then 2x-10+4x+40 = 90
Simplifying LHS gives 6x+30 = 90, and thus 6x = 60 or x = 10

Substituting this value of x into 2x-10 and 4x+40 gives:

angle a = 2(10)-10 = 10, angle c = 4(10)+40 = 80

To check; angle a + angle c = 10+80 = 90, this is complimentary.

More information is needed regarding angle b.