Respuesta :

Imstillhuman

Answer:

x = 7

Step-by-step explanation:

All the angles in a triangle added together equals 180 so:

64 + 71 + 9x - 18 = 180

add like terms

9x + 135 - 18 = 180

9x + 117 = 180

subtract 117 from both sides

9x = 63

divide by 9

x = 7

Answer:

x=7

Step-by-step explanation:

A triangle equals 180 and 64+71 is 135. 180-135 is 45. 9x-18=45.