Question

PLEASE HELP!!!

I don't understand.....
It would help if you could explain as well...
Thanks

Answer 1

x=9

Explanation:

steps shown in picture

Answer 2

Okay since this triangle is an isosceles triangle line AC and BC are congruent, meaning they’re equal length. Therefore, the equation to solve for X is...
20 = 3x - 7
27 = 3x
X = 9
Incase you want to find what line BC equals you just plug x into the equation so..
3(9) - 7 = 20