Final answer:
To find the value of x in the expression 4x - 30 and x - 15, we can set up an equation and solve for x.
Step-by-step explanation:
To find the value of x, we need to set up an equation based on the fact that the two expressions are complementary. The sum of two complementary angles is 90 degrees. So, we can set up the equation:
4x - 30 + x - 15 = 90
Combine like terms:
5x - 45 = 90
Add 45 to both sides:
5x = 135
Divide both sides by 5:
x = 27
Learn more about Complementary angles