Question

~Medal+Fanning~
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.

Answer 1

He made no mistake. You can substitute the value of x and y that he found look try. If x=2, y=0, 3x + y = 6 will be 3*2+0=6; x − 2y = 2 will be 2-2*0=2. So Henri made no mistake.

Answer 2

There, HelloGoodmorning.

Answer 3

Thank you Chineseboy :D

Answer 4

You are welcome!