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6c - (3 - 3c) = 24
Distribute the negative sign with terms inside the parenthesis;
6c - (3) - (-3c) = 24
6c - 3 + 3c = 24
Combine like terms:
9c - 3 = 24
Add 3 to both sides:
9c = 27
Divide both sides by 9:
c = 3.
50+79=129
180-129=51
X=51
Explanations
Angles on a straight line add up to 180 degrees. So 180-101=79 degrees
50 degrees is an opposite angle so it moves into the internal angle.
Angles in a triangle add up to 180 so (180-50-79=51)
Ans is 51 I think
10. is f 11. is a I dont know for 12 though