2x + y = 3
x - 2y = -1

if equation one is multiplied by 2 and then the equations are added, the result is

3x = 2
3x = 5
5x = 5

multiply 2x+y = 3 by 2

4x + 2y = 6

x - 2y = -1

add terms (be careful about signs!)

5x + 0 = 2

step-by-step explanation:

the multiplicative inverse of a fraction a/b is b/a. for the multiplicative inverse of a real number, divide 1 by the number. for example, the reciprocal of 5 is one fifth 1/5 or 0.2, and the reciprocal of 0.25 is 1 divided by 0.25, or 4.