Answer:
x = 27
Step-by-step explanation:
the 2 angles form a straight line and sum to 180° , that is
3x + 9 + 90 = 180
3x + 99 = 180 ( subtract 99 from both sides )
3x = 81 ( divide both sides by 3 )
Answer: 3(x+3)
Step-by-step explanation: 3x+9 then factor out 3 = 3(x+3)
