Answer:
Step-by-step explanation:
8.
slope=(83-3)/(10-0)=80/10=8
y-3=8(x-0)
y=8x+3
when x=20
y=8(20)+3=163
243=8x+3
243-3=8x
8x=240
x=240/8=30
when x=40
y=8*40+3=320+3=323
9.
(0,8) and (5,6)
m=(6-8)/(5-0)=-2/5=-0.4
y-8=-0.4(x-0)
y=-0.4x+8
