Question

2x + 3y = 6

5x + 2y = 4

Which of the following equations could be the result of multiplication and addition to eliminate a variable in the system of equations?

Answer 1

multiply eq.1 by 2 and eq. 2 by 3
and then subtract

Answer 2

y wil get eliminated

Answer 3

11y=22

Answer 4

actually i believe you would multiply the equation by -2 and then the second one by 3

this will give you

-4x + -6y = -12

15x + 6y = 12

because when you combine them....you add...THIS was -6y and +6y cancel out

so you would have

-4x + 15x is? 11x
-6y + 6y is? 0
-12 + 12 is? 0

so you have 11x = 0
x would equal 0....

you can do the same thing to solve for y

multiply the top one by -5 and the bottom one by 2...this will make the x's cancel

-10x - 15y = -30

10x + 4y = 8

now when you combine them you have

-10x + 10x is? 0
-15y + 4y is? -11y
-30 + 8 is? -22

so you have

-11y = -22
divide both sides by -11

y = 2

now check

2(0) + 3(2) = 6
0 + 6 = 6 yes
5(0) + 2(2) = 4
0 + 4 = 4 yes

so those are your answers :)

Answer 5

so y =2
then find x

Answer 6

5x + y = 6

5x + 3y = -4

The y-coordinate of the solution to the system shown is ___.

Answer 7

so you would do the same thing...just solve for y

how do we get y by itself? eliminate x
multiply the top equation by -1

-5x - y = -6
5x + 3y = -4

now when you add the two...the x's cancel out

so we have

2y = -10
divide both sides by 2

y = -5

this would be the y coordinate :)

Answer 8

7x - 3y = 4

2x - 4y = 1

Which of the following systems is not the same as solving the system shown?