The sum of two numbers is 48.One number is 3 times as large as the other. What are the numbers?

Question

shane_b · Answer

x+y=48
x=3y

Now just solve for x and y (I'd use the substitution method for this one)

blaque678 · Answer

thats where i get confused

tyteen4a03 · Answer

Which part are you confused? By substitution you substitute x=3y into x+y=48, which will become 3y+y = 48. Solve this equation to get the value of y, then use y to get x.

blaque678 · Answer

when it comes to breaking it down and subsitituing

shane_b · Answer

You have 2 equations with 2 unknown values:
x+y=48 
x=3y 

Using the substitution method you'd take the second equation which tells you exactly what x equals and plug it into the first equation anywhere you see an x:
(3y)+y=48
4y=48
y=12

Now you know what y is.  Use either of the original equations plugging in y to solve for x:
x + y = 48
x+12=48 (plug in y=12)
x=48-12=36

Therefore, x must equal 36 and y = 12.