If i'm not wrong its distributing property of addition. <span />
Answer:
Right angles is 90° so 90°+30°=120°.A straight line is 180°. So you do 180°-120° which is 60. So A=60°
Answer:
that is the way of calculating by using synthetic division
3s+7=S+5
-7 -S
2s = -2
S= -1