D
Step-by-step explanation:
80 divided by 2 equals 40 and if you multiply it by 8 its 320 so the constant number is 40. So y=40x mean y=40^x
y=-2.5x+12.5
step-by-step explanation:
5y=2x+10
y=0.4x+2
slope=-2.5
5=-2.5*3+b
b=12.5