Answer:
129 is x
Step-by-step explanation:
Your equation would be like this x= 45 + 6=180 (180 because the sum of the angle measures in a triangle is 180 always)
so once you add 45+6 =51 the equation is now x=51=180 so you subtract 51 from both sides so it equals as this x=51=180
x =-51= -51
x= 129
