Question

You are given the system of equations to solve by the elimination method, which is an INCORRECT step that will NOT produce a system with the same solution? 2x + y = −10 3x + 4y = −20

Answer 1

The solution of system of equation is (-4,-2)

Explanation:

The given system of linear equation is

Equation 1: 2x+y=(-10)

Equation 2: 3x+4y=(-20)

Using the Elimination method:

Important step: First multiply equation 1 by 4

we get,

Equation 3: 4(2x+y)=(-40)

Equation 3: 8x+4y=(-40)

Now,

8x+4y=-40 Equation 3

3x+4y=-20 Equation 2

- - +

________

5x+0=(-40)+20

5x=(-20)

x=(-4)

Replacing value of x i any equation

2x+y=(-10)

2(-4)+y=(-10)

(-8)+y=(-10)

y=(-2)

Thus,

The solution of system of equation is (-4,-2)