How do you solve the following system: 2x + y = 8 , x-10y=10 ?

1 Answer
Jan 15, 2016

The solution is
color(blue)(x = 30/7
color(blue)(y = -4/7

Explanation:

color(blue)(2x) +y = 8.........equation (1)

x -10y = 10, multiplying by 2
color(blue)(2x) -20y =20....equation (2)

Solving by elimination:
Subtracting equation 2 from 1

cancelcolor(blue)(2x) +y = 8
-cancelcolor(blue)(2x) +20y =-20

21y = -12

y = -12/21

color(blue)(y = -4/7

Finding x from equation 2:
x -10y = 10

x = 10+ 10y

x = 10+ 10 xx -4/7

x = 10 -40/7

x = 70/7 -40/7

color(blue)(x = 30/7