PSAT Math : Distributive Property

Study concepts, example questions & explanations for PSAT Math

varsity tutors app store varsity tutors android store

Example Questions

← Previous 1

Example Question #1 :Foil

Possible Answers:

Correct answer:

Explanation:

Example Question #1 :Distributive Property

If, what is the value of?

Possible Answers:

Correct answer:

Explanation:

Remember that (a –b)(a+b) =a2b2.

We can therefore rewrite (3x –4)(3x+ 4) = 2 as (3x)2– (4)2= 2.

Simplify to find 9x2– 16 = 2.

Adding 16 to each side gives us 9x2= 18.

Example Question #2 :Distributive Property

Ifand, then which of the following is equivalent to?

Possible Answers:

Correct answer:

Explanation:

We are asked to find the difference between g(h(x)) and h(g(x)), where g(x) = 2x2– 2 and h(x) = x + 4. Let's find expressions for both.

g(h(x)) = g(x + 4) = 2(x + 4)2– 2

g(h(x)) = 2(x + 4)(x + 4) – 2

In order to find (x+4)(x+4) we can use the FOIL method.

(x + 4)(x + 4) = x2+ 4x + 4x + 16

g(h(x)) = 2(x2+ 4x + 4x + 16) – 2

g(h(x)) = 2(x2+ 8x + 16) – 2

Distribute and simplify.

g(h(x)) = 2x2+ 16x + 32 – 2

g(h(x)) = 2x2+ 16x + 30

Now, we need to find h(g(x)).

h(g(x)) = h(2x2– 2) = 2x2– 2 + 4

h(g(x)) = 2x2+ 2

Finally, we can find g(h(x)) – h(g(x)).

g(h(x)) – h(g(x)) = 2x2+ 16x + 30 – (2x2+ 2)

= 2x2+ 16x + 30 – 2x2– 2

= 16x + 28

The answer is 16x + 28.

Example Question #1 :Foil

The sum of two numbers is. The product of the same two numbers is. If the two numbers are each increased by one, the new product is. Findin terms of.

Possible Answers:

Correct answer:

Explanation:

Let the two numbers bexandy.

x+y=s

xy=p

(x+ 1)(y+ 1) =q

Expand the last equation:

xy+x+y+ 1 =q

Note that both of the first two equations can be substituted into this new equation:

p+s+ 1 =q

Solve this equation forq – pby subtractingpfrom both sides:

s+ 1 =qp

Example Question #2 :Foil

Expand the expression:

\dpi{100} \small (x^{3}-4x)(6 + 12x^{2})

Possible Answers:

\dpi{100} \small 42x^{3}+12x^{5}-24x

\dpi{100} \small 12x^{5}-42x^{3}-24x

\dpi{100} \small 22x^{2}

\dpi{100} \small 6x^{3} + 12x^{2}-24x-48

\dpi{100} \small 6x^{3} + 12x^{5}-24x-48x^{3}

Correct answer:

\dpi{100} \small 12x^{5}-42x^{3}-24x

Explanation:

When using FOIL, multiply the first, outside, inside, then last expressions; then combine like terms.

\dpi{100} \small (x^{3}-4x)(6 + 12x^{2})

\dpi{100} \small 6x^{3}+12x^{5}-24x-48x^{3}

\dpi{100} \small -42x^{3}+12x^{5}-24x

\dpi{100} \small 12x^{5}-42x^{3}-24x

Example Question #2 :Distributive Property

Expand the following expression:

(4x+2)(x^2-2)

Possible Answers:

4x^3+2x^2-8x-4

x^3+2x^2-8x-4

4x^3-4

4x^3+4x-4

4x^3+2x^2+8x+4

Correct answer:

4x^3+2x^2-8x-4

Explanation:

(4x+2)(x^2-2)=(4x\times x^2)+(4x\times -2)+(2\times x^2) +(2\times -2)

Which becomes

4x^3-8x+2x^2-4

Or, written better

4x^3+2x^2-8x-4

Example Question #2 :How To Use Foil In The Distributive Property

Which of the following is equal to the expression?

Possible Answers:

Correct answer:

Explanation:

Multiply using FOIL:

First = 3x(2x) = 6x2

Outter = 3x(4) = 12x

Inner = -1(2x) = -2x

Last = -1(4) = -4

Combine and simplify:

6x2+ 12x - 2x - 4 = 6x2+10x - 4

Example Question #3 :Foil

Simplify the expression.

Possible Answers:


None of the other answers

Correct answer:

Explanation:

Solve by applying FOIL:

First: 2x2* 2y = 4x2y

Outer: 2x2* a = 2ax2

Inner: –3x * 2y = –6xy

Last: –3x * a = –3ax

Add them together: 4x2y + 2ax2– 6xy – 3ax

There are no common terms, so we are done.

Example Question #5 :Distributive Property

Given the equation above, what is the value of?

Possible Answers:

Correct answer:

Explanation:

Use FOIL to expand the left side of the equation.

From this equation, we can solve for,, and.

Plug these values intoto solve.

Example Question #4 :Distributive Property

Expand and simplify the expression.

Possible Answers:

Correct answer:

Explanation:

We can solve by FOIL, then distribute the. Since all terms are being multiplied, you will get the same answer if you distribute thebefore using FOIL.

First:

Inside:

Outside:

Last:

Sum all of the terms and simplify. Do not forget thein front of the quadratic!

最后,分配.

← Previous 1
Learning Tools by Varsity Tutors