Question 309023
Basic facts:

1. Two angles are said to be complimentary to each other when they add up to 90 degrees

Let us consider the smaller angle as x degrees
Therefore the larger angle will be (x + 10) degrees

As the angles are complimentary they add upto 90 degrees. Hence the equation can be written as:

x + (x+10) = 90
or, x + x + 10 = 90
or, 2x + 10 = 90
or, 2x + 10 - 10 = 90 - 10   (subtracting 10 from both sides)
or, 2x = 80
or, 2x/2 = 80/2   (dividing both sides by 2)
or, x = 40

Hence the smaller angle is 40 and the larger angle is (40 + 10) 50 degrees.