A) A linear equation is written in the form y=mx+b, here we are substituting C (total cost) for y and n (number of toys) for x.

The total cost to develop n toys would be the initial development cost plus the manufacturing cost of each toy.

m is going to equal the cost to develop a toy because it is multiplied by n, the number of toys.

b is going to equal the development cost because it is a constant and does not change with the number of toys.

Therefore, C=15n + 1400

B) Now take the equation we just wrote for C and plug in n=1750

C= 15(1750) + 1400

C= 26250+1400

C= $27,650

C) Now, we use the same equation, but we are given C instead of n.

71150= 15n +1400

71150-1400 = 15n

69750= 15n

Now, divide both sides by 15 to get n by itself:

69750/15= n

n= 4650