Subtract three from either side. That will give you 4r=-21. Divide -21 by 4 and r will equal -5.25.
The answer would be Find 40% of 20 because you would round 43% down and 18 up. Hope this helps :)
The 2 angles add up to 90 degrees so
x + y = 90, also:-
x - y = 72 (given)
adding the 2 equations:-
2x = 162
x = 81
and therefore
y + 81 = 90
y = 9
Answer the 2 angles are 81 and 9 degrees
