How to factor this expression: x^2-9?

Mathematics

1 answer:

Lena [83]2 years ago

7 0

Answer:

(x+3)(x-3)

Step-by-step explanation:

rewrite "9" as 3^2

so it is x^2-3^2

You use the difference of squares: a^2-b^2=(a+b)(a-b)

apply it: (x+3)(x-3)

You might be interested in

there are two food trucks for sale that would be perfect for your business. the blue food truck is in perfect condition, but 8,0

Gennadij [26K]

Answer:

blue truck-$82000 green truck-$90000

Step-by-step explanation:

x+8000=y

x+y=172000

7 0

3 years ago

The volume of a cube is 1000cm3. Find:

Gala2k [10]

Length of one edge is 10cm
And the surface area is 600cm2

5 0

3 years ago

Read 2 more answers

If cells are: a1=90, a2=85, a3=80, a4=75, and a5=75. what will be your formula if you are going to get the average?

swat32

The average can be given by the following formula:
Average = (a1 + a2 + a3 + a4 + a5) / (5).
Equivalently.
Average = (ai) / (i).
Where,
i = 1,2,3,4, ..., n
Substituting
Average = (90 + 85 + 80 + 75 + 75) / (5).
Average = 81
answer:
Average = (a1 + a2 + a3 + a4 + a5) / (5).
or
Average = (ai) / (i).
Where,
i = 1,2,3,4, ..., n

8 0

3 years ago

A metallurgist has one alloy containing 32% copper and another containing 65% copper. How many pounds of each alloy must he use

kompoz [17]

Answer:

<h2>30.67 pounds of 32% copper alloy and 10.33 pounds of 65% copper alloy</h2>

Step-by-step explanation:

First alloy contains 32% copper and the second alloy contains 65% alloy.

We wish to make 44 pounds of a third alloy containing 42% copper.

Let the weight of first alloy used be $x$ in pounds and the weight of second alloy used be $y$ in pounds.