HELP AND WILL GIVE BRAINLIEST!!! Solve for x

Answer:
let the opposite angle of 43=y
57°+43°+y=180°[by sum of all angle is 180°]
100+y=180°
y=180°-100
y=80°
opposite angle of x is equal to the 80°
so the equation will be like this
x+x+80°=180°
2x+80°=180°
2x=180°-80°
2x=100
x=100/2
x=50°
so the value of x is 50°