Answer:
x=5
Step-by-step explanation:
We know that the angels in a triangle are equal to 180.
(6x+20)+(7x-10)+105=180
We open the prentices and simplify.
13x+115=180
Now we can subtract 115 on both sides.
13x=65
At last, we can divide by 13 on both sides to get the result of x.
x=5
