Question

I need help on that, please and thank you.​

Answer 1

X = 180 - (31 + 40)

Explanation:

X + 31° + 40° = 180° { angle on a straight line is 180°}

Collecting like terms

X = 180° - 31° - 40°

X = 180° - (31° + 40°)

X = 180° - 71°

X = 109°

Answer 2

it’s number three. have a good day. :)