Question 992198
Twice a number minus a second number is -1. Twice the second number added to three times the first number is 9. Find the number.

let x=number
let y=2nd number
2x-y=-1
y=-2x+1
plug in y for x

2(-2x+1)+3x=9
-4x+2+3x=9
x=7
 number=7