Question

A yearbook printer charges based on the number of pages printed. Here is a table that shows the cost of some recent yearbooks.

Answer 1

So y=mx+b

cost=m(number of pages)+b

cost=y
# of pages=x


so points are
(x,y)
(50,1.55)
(100,2.25)
(150,2.95)
(20,3.65)


so solve for slope/m you do  (y₁-y₂)/(x₁-x₂) so
just use any for example
(1.55-2.25)/(50-100)=-0.70/-50=1 times 0.7/50=7/500= (to convet to decimal form) 14/1000=1.4/100=0.14/10=0.014/1=0.014

slpoe is 0.014

y=0.014x+b

input one of the points exg 50 for x and 1.55 for y and solve for b
1.55=0.014(50)+b
1.55=.7+b
subtract .7 from both sides
0.85=b

so the equation is
y=0.014x+0.85

which is C