Question

Henri solved the system of equations below. What mistake did he make in his work?
3x + y = 6
x − 2y = 2

y = 6 − 3x
x − 2(6 − 3x) = 2
x − 12 + 6x = 2
7x − 12 = 2
+ 12 +12
7 x over 7 equals 14 over 7
x = 2

3(2) + y = 6
6 + y = 6
−6 −6
y = 0

He should have substituted 6 + 3x.

He combined like terms incorrectly. It should have been 5x instead of 7x.

He made a mistake in distributing −2.

He made no mistake.

The wonderful @Mertsj is on! Can you help?

Answer 1

There is no mistake. he did it right lml. I checked by using the elimination method.

Answer 2

D.

Answer 3

You could check if there is a mistake by replacing x with 2 and y with 0 in the two original equations. If they are both true (and they are) then he make no mistake.

Answer 4

Thanks!

Answer 5

yw