A printer will produce 80 wedding invitations for $210. The price to produce 120 invitations is $290. The printer uses a linear function to determine the price for producing different amounts of invitations. How much will the printer charge to produce 60 invitations?
$120.00
$145.00
$157.50
$170.00

Question

A printer will produce 80 wedding invitations for $210. The price to produce 120 invitations is $290. The printer uses a linear function to determine the price for producing different amounts of invitations. How much will the printer charge to produce 60 invitations?
$120.00
$145.00
$157.50
$170.00

mathmate · Answer

Hint:
Use the equation  
y=mx+b
where m=(y2-y1)/(x2-x1)

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anonymous · Answer

i did m=(y2-y1)/(x2-x1) and got 2

anonymous · Answer

so y = 2x + b

anonymous · Answer

@mathmate

mathmate · Answer

Good! 
Now can you find b, knowing that when x=80, y=210?