Question

X + 5y = 202x - 7y=-45Solve by eliminations

Answer 1

We have the system:

x + 5y = 20

2x - 7y = -45

Using the elimination method, we'll have

x+ 5y = 20 *(-2)

2x - 7y = -45

-2x -10y = -40

2x -7y= -45

Adding the equations:

-17y = -85

y = 5

So:

2x - 7*5 = -45

2x - 35 = -45

2x = -45+35

2x = -10

x= -5

Solution: S= {-5,5}