The sum of two numbers 100. One number is 10 less than 4 times the other.

Question

Please help me! Algebra is my worst subject and I need help!

Answer 1

The sum of two numbers 100. One number is 10 less than 4 times the other.

Let's use x and y to represent our numbers.

We know x+y=100

We also know that "one number is 10 less than 4 times the other number. So we can say that y=4x-10

Here's how I got the above equation.

4 times=4x

10 less than 4 times=4x-10

Now here is our system of equations:

x+y=100

y=4x-10

Solve using any method you like. I would use substitution for this problem. I would substitute the second equation into the first one. So it would look like this:

x+4x-10=100

From there, solve for x. Then, substitute that answer for x in the first equation to solve for y.

Good luck!

Answer 2

number 1: x

number 2: y

y in terms of x: y = 4x - 10

x + y = 100

plug in y in terms of x equation:

x + (4x-10) = 100

5x - 10 = 100

5x = 110

x = 22

plug value of x in for y equation

y = 4 (22) - 10

y = 88-10

y = 78

plug answers back in to double check:

22 + 78 = 100

Hope this helps! :)