Respuesta :

Marwana2465

Answer: 18) (9x)° + 45° = 180°-45°= 135° then we isolate the variable and the answer is 9x/9 which is equal to x = 15°.

Step-by-step explanation: 18) supplementary angles add up to 180 degrees. So a supplementary angle lies on a single, straight line
19) (4x)° + 26 = 90 because complementary angles add up to 90° which is a right angle we do 90-26 = 64 and then isolate the variable 4x/4 and 64/4 and get 1