Answer:
Part 1: 31x+25=180
part 2: x=5
Explanation:
there are 180° on a straight line, which is the base/ bottom line of the traingle (indicated by the arrow on the end).
so, 180-151= 29
29° is the third angle on the traingle.
now, there are 180° in a triangle, therefore to find an equation for x:
29+20x-3+11x-1= 180 (adding up all the angles and making it equal to 180°)
now simplify this equation to get:
31x+25=180 (PART 1)
to find x simply solve the equation:
31x=180-25
31x= 155
x= 155/31
x=5 (PART 2)