The relationship between the cost, y, in dollars, of x pounds of concrete can be modeled by a proportional equation.

Part A: 1.20 is y=20 is x

Part B= 9$

Step-by-step explanation:

Part A: if we notice our chart we will see that 4.80=80 so what we could do is say 1.20$ equals 20 pounds of concrete (you can do this differently for example 0.60$=10 pounds of concrete, but I just chose 20.)  

Part B: If we want to find how much 150 pounds of concrete is we will first add 20 pounds 3 times giving us 140 pounds and then we split 20 and get 10, which equals 150, then we have to do the same thing for the cost, so 4.80+3.60=8.40 and then we split 1.20 in half giving us 0.60 which we then add to get 9$.

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step-by-step explanation:

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