# Homework Help: Algebra - FOIL Bi/Tri nomials to the nth power

1. Aug 3, 2011

### Miike012

I added an attachment with my question highlited.

How was the coeficient 6, 4, and 1 determined.

by rule 6 the coeficient should be 8*3/(2+1) = 8.

Thank you.

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2. Aug 3, 2011

### Bohrok

It looks like you're supposed to look at the numbers in the line for Coefficients rather than the coefficients of the terms in the bottom line for Multiplying. The instructions on that page work out only if both terms in the binomial have a coefficient of 1.

3. Aug 3, 2011

### Miike012

Ok well how am I suppose to figure out the coefficient if that line isnt given?

4. Aug 3, 2011

### Bohrok

Instead of looking at the 8 in the bottom line, use the 4 right above it. Do the same thing for each following coefficient.

5. Aug 3, 2011

### Miike012

did that already.. it turns out that if I used the 4 instead of the 8.. the next coef. would be 4 rather than 6.. which doesnt work.

6. Aug 3, 2011

### Bohrok

Not only is that 2 in front of the b messing up the instructions, but that 2 exponent is too...
Before you actually use the exponent on your b to get the next coefficient, divide it's exponent by the exponent that b has in the original binomial in parentheses; in this case divide the exponents of b by 2 before you actually use them to find the coefficient.

7. Aug 3, 2011

### Miike012

thank you. it makes sence now. I will be starting calc this upcoming semester, will this technique be useful?

8. Aug 3, 2011

### Bohrok

Probably not; I don't think I saw binomial expansions at all in calc I or II.