Exercise 6 Page 547

We know the measures of two complementary angles. The measure of ∠ B is (4x)^(∘) and the measure of ∠ A is 50^(∘).

Since the angles A and B are complementary, we know that the sum of their measures should equal 90^(∘). We can solve for x by creating an equation using the expressions for the two smaller angles and their sum.

4x + 50 = 90

SubEqn

LHS-50=RHS-50

4x = 40

DivEqn

.LHS /4.=.RHS /4.

4x/4 = 40/4

CalcQuot

Calculate quotient

x = 10