Find the Numbers

[nycmathguy]

Two numbers add up to 72. One number is twice the other. Find the numbers.

Let me see.

Let x and y be the two numbers.

x + y = 72...Equation A

One number is twice the other.

x = 2y...Equation B

Plug B into A to find y.

2y + y = 72

3y = 72.

y = 72/3

y = 24

Plug y = 24 into either equation to find x.

I will use x = 2y.

x = 2(24)

x = 48

The two numbers are 24 and 48.

 

[MathLover1]

correct

 

[nycmathguy]

correct

A nice, easy problem to start the night.

 

[HallsofIvy]

Two numbers add up to 72. One number is twice the other. Find the numbers.

Let me see.

Let x and y be the two numbers.

x + y = 72...Equation A

One number is twice the other.

x = 2y...Equation B

Plug B into A to find y.

2y + y = 72

3y = 72.

y = 72/3

y = 24

Plug y = 24 into either equation to find x.

I will use x = 2y.

x = 2(24)

x = 48

The two numbers are 24 and 48.

It is not difficult to CHECK yourself:
"Two numbers add up to 72."
Do 24 and 48 add to 72? Yes, they do!

"One number is twice the other."
Is 48 twice 24? Yes, it is!

 

[nycmathguy]

It is not difficult to CHECK yourself:
"Two numbers add up to 72."
Do 24 and 48 add to 72? Yes, they do!

"One number is twice the other."
Is 48 twice 24? Yes, it is!

I could have checked myself but MathLover1 enjoys helping me in so many ways since we met at algebra.com.