Question

How do you solve `5x+y=5` and `10x + 3y = 20`?

Answer 1

See explanation.

Explanation:

The system is:

`{(5x+y=5),(10x+3y=20):}`

If you multiply the first equation by `-2` the oefficients of `x` will be opposite:

`{(-10x-2y=-10),(10x+3y=20):}`

If you add both equations you get:

`y=10`

Now you can substitute the calcukated value to the first equation to calculate the value of `x`:

`5x+10=5`

`5x=-5`

`x=-1`

Answer:

The solution is:

`{(x=-1),(y=10):}`