In cases like these, you simply have to multiply the choices you have for each step.
In fact, you can choose between 4 different crusts. For each of these crusts you can choose 4 different sauces. This means that there are
choices at this point. In fact, if we call the crust options 1,2,3,4 and the sauce options A,B,C,D, the 16 possible combinations are

From here, you keep going multiplying the number of options for each step, for a total of

Are you sure you want ONLY the coefficient of b? If you expand this, you will have b in 3 of 4 terms.
According to Pascal's Triangle, the coefficients of (a+b)^4 are as follows:
1
1 2 1
1 3 3 1
1 4 6 4 1
So (a+b)^4 would be 1a^4 + 4a^3b + 6a^2b^2 + 4ab^3 + b^4
Here, you want (3 + b)^4. Here's what that looks like:
3^4 + 4[3^3*b] + 6[3^2*b^2] + 4[3*b^3] + 1[b^4]
Which coeff did you want?
Answer:y=0.5x+10
Step-by-step explanation:
need help with explanation?