The difference between 2 positive numbers is 9. If 4 times the larger number is 10 times the smaller, what is the larger number?
Let L = larger number
Let S = smaller number
L - S = 9
4L = 10S
After doing the math, I came up with the larger number being 90.
According to the math book, my answer is wrong.
What did I do wrong?
Are the equations wrong?