Question

the area of desert A is four times the area of desert B. if the sum of their areas are 2,000,000 square miles, what is the area of each desert?

Answer 1

Let's start by turning what we know into equations. Desert a is four times the area of desert b. So a = 4*b. Desert a plus desert b is 2000000 square miles. So a+b=2million.
Take our second equation and substitute 4b in for a since we know a=4b.
(4b)+b=2,000,000
Once simplified, we see b=400,000 which means desert b is 400,000 square miles.
Then, we can substitute 400,000 in for b in either equation, I used the first.
a=4(400,000)
Simplified, we see a=1,600,000.
So desert a is 1,600,000 square miles.
To check our work, we can plug in both values to one equation.
a+b=2,000,000
(1,600,000)+(400,000)=2,000,000
Since 2,000,000 does equal 2,000,000, we know we got the right answer.

Answer 2

A= 4B (because the area is 4 times that of the area of B)

Now add their areas together.

B + 4B = 2,000,000 square miles
5B= 2,000,000
Divide both sides by 5
B= 400,000 square miles= area of desert B

4B= 1,600,000 square miles = area of desert A

Hope this helps!! :)