Question

someone help please :(
What is the value of the x variable in the solution to the following system of equations?

4x + 2y = 6
x – y = 3

−1

5

−2

2

Answer 1

There are several ways to solve this. The method I'd use is to double the bottom equation. If you double everything, the statement remains true. So you get
4x+2y=6
2x-2y=6
--------Now, add the two equations, so you get
6x=12

So x=2.

Answer 2

i agree with vinnv226 the answer is 2 so therefore he is right

Answer 3

thank you!

Answer 4

Solve one equation fory, lets say we take the second one.

x - y = 3

Solving for y,we would subtract -x from both sides.

-y = -x + 3

multiply the entire equation by -1

-1(-y = -x + 3)

Simplify

y = x - 3

Substitute into the first equation.

4x + 2y = 6

4x +2(x-3) = 6

Simplify

4x +2x -6 = 6

Add +6 to both sides

6x = 12

divide by 6

x = 2

Answer 5

youre right! jhannybean! thank you

Answer 6

No problem :)

Answer 7

can you help me with another equation?

Answer 8

Showed you two different methods of solving the same problem - elimination and substitution :D

Answer 9

Sure thing.

Answer 10

The three Math Idol judges have been eliminating contestants all day! The number of one-step equations and two-step equations who have been eliminated today is equal to 1150. If three times the number of one-step equations minus twice the number of two-step equations is equal to 1300, how many one-step equations eliminated today?

430

720

1150

1300

Answer 11

Lets say the one step equations are x and the two step equations = y

Your first statement: The number of one-step equations and two-step equations who have been eliminated today is equal to 115

We can rewrite this as the combination of both equations = total # :1150

\(\color{red}{x+ y = 1150}\)

Second statement: If three times the number of one-step equations minus twice the number of two-step equations is equal to 1300

\(\color{blue}{3x-2y=1300}\)

Third statement : how many one-step equations eliminated today?

\(\color{purple}{x=?}\)

Answer 12

umm is it 720?

Answer 13

We can use @vinnv226 'smethod to evaluate this faster.

x + y = 1150
3x - 2y = 1300
------------- We want to eliminate the y's, so we multiply the whole equation by 2

2(x+y =1150)
3x - 2y = 1300
------------------

2x + 2y = 2300
3x - 2y = 1300
-------------------

6x = 3600

x = 3600/6

Answer 14

your answer choices seem a bit off....

Answer 15

I copied and pasted them exactly from the quiz

Answer 16

@jhannybean you added 2x+3x and got 6x, you should have put 5x. So the answer is 3600/5 which is 720.

Answer 17

thank you! :)

Answer 18

Oh yes you are right, whoops. then you are right, haha. Sorry about that.