Question

Please help! Algebra 2!!

Answer 1

Mistake found

3x-2(2x-4)=2

3x - 4x - 8 = 2 instead of 3x - 4x + 8 = 2

Correct answer

x= -13 y= -30

Answer 2

Answer:

See below.

Step-by-step explanation:

So we have the system of equations:

$3x-2y=21 \text{ and } y=2x-4$

The student took the following steps:

$3x-2(2x-4)=21\\3x-4x-8=21\\-x-8=21\\-x=29\\x=-29\\y=2(-29)-4=-58-4=-62$

The student's mistake is in step 2. He/she distributed incorrectly. You are supposed to distribute the -2 to both terms, so it should be -4x plus 8, since -2 times -4 is positive 8. Fixing that mistake, we will have:

$3x-2(2x-4)=21\\3x-4x+8=21 \\-x+8=21\\-x=13\\x=-13\\y=2(-13)-4=-26-4=-30$

Thus, the final answers should be (-13, -30).