50. If angles are complementary, what’s value of x?

Answer:
x = 14
Step-by-step explanation:
For complementary angles, the sum of two angles is equal to 90 degrees.
We have,
[tex]m\angle ABC = 4x-10\\\\m\angle DBC = x+30[/tex]
ATQ,
[tex]4x-10+x+30=90[/tex]
Taking like terms together,
4x+x =90-30+10
5x = 70
x = 14
So, the value of x is 14.