How do you find the product (2a+9)(5a-6)?

1 Answer
Apr 23, 2017

10a^2+33a-54

Explanation:

Notice that these are factors.

You can use the FOIL method or the Distributive Property .

What is FOIL ???

FOIL- First Outer Inner Last

(2a+9)(5a-6)

First: Multiply the first term in the first factor with the first term in the second factor. NB: both numbers are the first of both factors.

2axx5a=10a^2

Outer: Multipy the first term in the first factor with the last term in the second factor. NB: both numbers are the last of both factors.

2axx-6=-12a

Inner: Multiply the last term in the first factor with the first term in the second factor. NB: both numbers are innermost numbers.

9xx5a=45a

Last: Multiply the last term in the first factor with the last term in the second factor. NB: both numbers are the last numbers of each factor.

9xx-6=-54

Now add the numbers.

10a^2+(-12a)+45a+(-54)

10a^2-12a+45a-54

10a^2+33a-54

What is the Distributive Property ???

The distributive property is simply taking the first term in the first factor and multiplying it by the second term.

2a(5a-6)=10a^2-12a

Next, take the second term in the first factor and mutilply it by the second factor.

9(5a-6)=45a-54

Add the products

(10a^2-12a)+(45a-54)

10a^2-12a+45a-54

10a^2+33a-54

I hope this was well explained.

Follow the same steps and try to solve (5x-3)(6+8x)

You should get 40x^2+6x-18 as the answer.

All the best!