Answer:
1) 16
2) 20
3) -12
4) 16
Explanation:
1) Substitute the r for 4 like it tells you in the question so 12 + 4 = 16.
2) Substitute d with -3 so 5(-3+7) = 5 x (4) = 20
3) Substitute m for 4 so -48 / 4 = -12
4) Angle of triangle is half base times height or 1/2 x b x h
And since the base is 4 and the height is 8:
1/2 x 4 x 8 = 1/2 x 32 = 16
Or in other words:
1/2 x 32 = 32 / 2 = 16