#1**+1 **

First one :

Since we have a segment parallel to a base of a triangle,the sides are in equal proportion...so....

121/ 11 = (5x + 10) / 10

11 = (5x + 10) / 10 multiply both sides by 10

110 = 5x + 10 subtract 10 from both sides

100 = 5x divide both sides by 5

20 = x

CPhill Dec 19, 2018