Answer:
x = 54
Explanation:
The two angles added together equal 90 degrees because they are complementary angles.
x - 18 + x = 90
Combine like terms
2x - 18 = 90
add 18 to both sides
2x = 108
Divide each side by 2
x = 54
Fill in for x
54 - 18 + 54 = 90
36 + 54 = 90
90 = 90
This proves that the answer is true.