The area of Sahara desert is 7 times the area of the Gobi Desert. If the sum of their areas is 4,000,000 square miles, find the area of each desert

X=area of Sahara.

y=area of the Gobi Desert.

We suggest this system equations:

x+y=4000000

x=7y

solve by susbstitution method.

(7y) + y=4,000,000

8y=4,000,000

y=4,000,000 / 8=500,000

x=7y

x=7 (500,000) = 3,500,000

The area of Sahara=3,500,00 miles².

The area of the Gobi Desert=500,000 miles²

To check:

Te sum of their areas is : 3,500,000 miles²+500,000 miles²=4,000,000 miles²

Te area of sahara (3,500,000 miles²) is 7 times the area of the Gobi Desert (7*500,000 miles²=3,500,000 miles²).