by MARIA
(SALT LAKE CITY, UT)
Alvin's age is three times Elga's age. The sum of their ages is " 40 ". What is Elga's age?
Let x be Alvin's age
Let y be Elga's age
x + y = 40
x = 3y
Replace x = 3y into x + y = 40
We get 3y + y = 40
4y = 40
4y/4 = 40 / 4
y = 10
So Elga is 10 years old
Alvin's age is x = 3y = 3 times 10 = 30
Comments for college student








Nov 20, 17 11:18 AM
What is a linear parent function? Crystal clear explanation.
New math lessons
Your email is safe with us. We will only use it to inform you about new math lessons.
Nov 20, 17 11:18 AM
What is a linear parent function? Crystal clear explanation.
Our Top Pages
Formula for percentage
Compatible numbers
Basic math test
Basic math formulas
Types of angles
Math problem solver
Algebra word problems
Surface area of a cube
Finding the average
Scale drawings
Everything you need to prepare for an important exam!
K12 tests, GED math test, basic math tests, geometry tests, algebra tests.
Real Life Math Skills
Learn about investing money, budgeting your money, paying taxes, mortgage loans, and even the math involved in playing baseball.