Question

Solve the system of equations by substitution. What is the solution for x?

2x + y = 1
4x + 2y = -2

x = 0

x = 2

There is no x value, as there is no solution.

x can be any value, as there is an infinite number of solutions.

Answer 1

@jim_thompson5910

Answer 2

i did this same question today...

Answer 3

choose the last option

Answer 4

rewrite eq.1
y=1-2x
sub it into eq.2
4x+2(1-2x)=-2
4x+2-4x=-2
2=-2

Answer 5

Lemme try Cramer's Rule for this one.

Answer 6

as u can see the x cancels so x can be any value, there will be an infinite # of solutions

Answer 7

\[\left[\begin{matrix}2 & 1 \\ 4 & 2\end{matrix}\right]\left[\begin{matrix}x \\ y\end{matrix}\right]=\left[\begin{matrix}1 \\ -2\end{matrix}\right]\]
\[AB=C\]
\[|A| = \left[\begin{matrix}2 & 1 \\ 4 & 2\end{matrix}\right] = (2\times2)-(1\times4)=0\]

Answer 8

This systems of equation doesn't work

Answer 9

im sorry i still dont understand

Answer 10

would the answer be 2=-2 @LynFran

Answer 11

There is no x value, as there is no solution.

Answer 12

That 2 lines are parallel

Answer 13

its not x can carry an infinite # of solution

Answer 14

@DecentNabeel check this out lol

Answer 15

x cannot be 0 and -2 at the same time in systems of equation.

Answer 16

So witch would it be ?

Answer 17

check this out its explain in more detail http://openstudy.com/users/decentnabeel#/updates/55b9661ee4b0adef802b9b51

Answer 18

If the determinant made from the coefficients equals zero, then there is not a single solution to the system.

Answer 19

did u do that by substitution""

Answer 20

Nah, I just put em in 2x2 matrix and get determinant

Answer 21

If |A| = 0 , the system of equation doesn't work cause you can't divide by zero

Answer 22

The original system of equations:
2x + y = 1
4x + 2y = -2

Modify the first equation:
y = 1 - 2x

Insert that into the second equation, then solve:
4x + 2(1 - 2x) = -2
4x + 2 - 4x = -2
4x - 4x + 2 = -2
2 = -2

The system of equations has no solution.

Answer 23

How can 2=-2

Answer 24

The point is that 2 does not equal 2. There is no solution to the system of equations.