the sum of 3 numbers is 90. the 2nd number is 2 times the 3rd. the 1st number is 10 more than the 3rd. what are these numbers?

Answer 1

Kylie,

Let us say the numbers are x, y and z.

x + y + z = 90

y = 2z

x = z + 10

We can technically put the whole equation in terms of z now.

(z + 10) + 2z + z = 90

4z + 10 = 90

4z = 80

z = 20

If z is 20, we know that y is 40 and x is 30.

And this makes sense because all these numbers add up to 90.

Hope this helps! :)