Question

Which of these systems of equations would be best solved using the subtraction​ method?

I. 2x−7y+3y = 4 −6x−4y = −52
II. 2y = −5x+6x−5 y = 2x−6
III. −7x+3x+2y = 4 4x−6y = −52

Answer 1

Explanation:

1. x+2y=6 or x=6-2y

3x-2y=2

3(6-2y)-2y=2

18-6y-2y=2

18-8y=2

-8y=-18+2

-8y=-16

y=-16/-8

y=2 ans.

x+2*2=6

x+4=6

x=6-4=2 ans.

Proof:

3*2-2*2=2

6-4=2

2=2

I leave the rest for you to practice with.

3. 4x+y=7

2x+5y=-1

5. 3x+2y=-2

6x-y=6

Solve the system using the elimination method. Show all your steps.

7. -3x+3y=3

3x+y=9 add.

---------------------------------

4y=12

y=12/4

y=3 ans.

3x+3=9

3x=9-3

3x=6

x=6/3

x=2 ans.

Proof:

-3*2+3*3=3

-6+9=3

3=3

I'll leave the rest for practice.

9. -5x+12y=20

x-2y=-6

11. 3x+2y=1

4x+ 6y= 7