I need help with an algebra problem?

You start by translating the English to mathematics. Write equations containing what you know.

The word "is" can be translated as an equals sign.

We'll let "X" be the smaller number, and "Y" be the larger number.

"The sum of two numbers is 15." --That should be pretty easy:

X + Y = 15, right?

The second equation is a little harder: "One less than three times the smaller is equal to the larger."

(3*X) - 1 = Y, right? Make sure that you understand this part!

You should be able to do the rest of the algebra from here. Start by replacing "Y" in the first equation, with it's equivalent (3*X)-1 from the second equation.

You are basically going to read the problem and turn it into an equation.

"The sum of two numbers is 15" = x+y=15

That's what your teacher is going to want to see.

Now the short cut is to work that problem out and see if it matches up with what the problem says. I don't want to work it out all the way for you otherwise you wont learn. But a possible answer could be the numbers 4 and 11. 4 times 3 is 12, minus 1 equals 11.

Sum of two numbers is 15,

let the smaller be x, larger be y

3x-1=y

x+y=15

x+3x-1=15

4x=16

x=4

y=11

11+4=15 //true

3*4-1=9//true

Conditions met, so your numbers are 11 and 4, it was confusing for me too in the beginning because it said the larger and smaller number, that's why I did it in two variables.

Have fun :)

You have two numbers x and y. The sum of x+y=15

If the smaller number is x then 3x-1=y

So x+3x-1=15

Can you finish this?

It is easy. Just make two algebraic equations.

X + Y = 15

X = (3 * Y) -1

Plug (3Y-1) into the first equation to get (3Y-1) + Y = 15

simplify to 4Y-1=15 or 4Y=16, Y=4

Plug the 4 into the first equation and you get X+4=15, which means X=11