# SAT Practice Math Questions—FOIL Operations

The SAT Math exam will throw some questions at you where you’ll be expected to know how to perform a FOIL operation—where you multiply a polynomial in the order, First, Outer, Inner, and Last.

The following practice questions ask you to find the product of two binomials and the value of a variable using the FOIL method.

## Practice questions

**Which of the following is the product of these two binomials?**

*x*+ 2

*x*– 5

**A.***x*^{2}**–**10

**B.***x*^{2}**+**10

**C.***x*^{2}**–**3*x*– 10

**D.***x*^{2}**+**3*x*– 10**If***x*– 2 is a factor of*x*^{2}+ 6*x*–*y*^{2}and*y*> 0, what is the value of*y*?

*Note:*this would be a grid-in question. Because there are no multiple-choice answers, you need to supply the correct answer.

## Answers and explanations

**The correct answer is Choice (C).**

Product means “multiply.” This is a simple FOIL operation:

(*x*+ 2)(*x*– 5) =*x*^{2}– 3*x*–10**The correct answer is 4.**

If*x*– 2 is a factor of the polynomial, then for the middle part of the polynomial to be 6*x*, the other factor must be (*x*+ 8). Write out these factors and FOIL the expression:

(*x*– 2)(*x*+ 8)

= (*x*^{2}+ 6*x*– 16)

The given polynomial is*x*^{2}+ 6*x*–*y*^{2}, so this means that*y*^{2}= 16, and because*y*is positive, it must equal 4.