en

English

Español

Português

Français

Deutsch

Italiano

Русский

中文(简体)

한국어

日本語

Tiếng Việt

עברית

العربية

Popular >

The sum of three numbers is 81. The third number is 2 times the first. The second number is 7 less than the first. What are the numbers?

Solution

The sum of three numbers is 81. The third number is 2 times the first. The second number is 7 less than the first. What are the numbers?

Solution

The numbers : 22, 15, 44

Solution steps

Represent the numbers with

x, y, z

:

number 1 : x

number 2 : y

number 3 : z

A.T.Q.:

x + y + z = 81

z = 2 x

y = x - 7

x + y + z = 81, z = 2 x, y = x - 7 : x = 22, y = 15, z = 44

The numbers : 22, 15, 44

Popular Examples

If a number is added to the numerator of 3/7 and the same number is subtracted from the denominator, the result is 4. Find the number.If 1200 is invested in an account that earns 9.01% compounded annually for 6 years, find the interest earned during each year and the amount in the account at the end of each year.The radius of a circle is 10 inches. What is the area?Twice the difference of a number and 4 equals 5.Each side of a square garden is 13 yards long. What is the garden's area?