Sum of complementary angles always equal to 90°.
Given, <A and <J are complementary angles. So, we can set up an equation as following:
m<A+ M<J= 90
Next step is to plug in m<A = 5x + 30 and m<J = 4x +15 in the above equation. So we will get,
5x+30+4x+15=90
(5x+4x)+(30+15)=90 Group the like terms.
9x+45=90 Combine the like terms.
9x+45-45=90-45 Subtract 45 from each sides.
9x=45 By simplifying.
[tex] \frac{9x}{9}=\frac{45}{9} [/tex] Divide each sides by 9.
x=5.
So, x=5.
