Craig solves the following system of equations using the elimination method.
2x+4y=16
4x+8y=−16
He chooses to eliminate the variable y.
Which statement correct describes his process and solution?
A) Craig multiplies 2x + 4y = 16 by 2 and then adds the equations. He finds the result is a contradiction, so there is no solution.
B) Craig multiplies 2x + 4y = 16 by 2 and then adds the equations. He finds the result is an identity, so there are infinitely many solutions.
C) Craig multiplies 2x + 4y = 16 by 2 and then subtracts the equations. He finds the result is an identity, so there are infinitely many solutions.
D) Craig multiplies 2x + 4y = 16 by 2 and then subtracts the equations. He finds the result is a contradiction, so there is no solution.

Question

yourdootcome · Answer

ok so try multiplying the first equation by 2 what do you get?

yourdootcome · Answer

you get 4x+8y=16 and see how the other one is 4x+8y=-16 that means there is no solution because both contradict each other

Lars · Answer

Ohh okay. So Craig is subtracting then

Lars · Answer

Or I think-

yourdootcome · Answer

no he multiplies the first equation by 2
2(2x+4y)=(16)*2 
= 4x+8y=32

yourdootcome · Answer

and it says that 4x+8y=-16 on the second equation which directly contradicts the first equation which means the answer is D because 32 does not equal -16

Lars · Answer

Ohh okay that clears up a bit of my confusion. Thank you