Dee asked in Science & MathematicsMathematics · 9 years ago

# Solve using the elimination method. Show your work. If the system has no solution or an infinite number of sol?

Solve using the elimination method. Show your work. If the system has no solution or an infinite number of solutions, state this.

-3x+4y=1, -6x+6y=-3

THIS IS WHAT I GOT

multiply yh first equation -3x+4y=1 by 2------- -6x+8y=1

then add 2nd equation -6x+6y=-3..... 12y=-2

y=-6

then -3x+4(-6)=1....-3x+-24=1

Relevance
• 9 years ago

Rewriting the equations:

-3x+4y=1

-6x+6y=-3

Multiply (-3x+4y=1) by 2 to get: -6x+8y=2

Once again rewriting:

-6x+8y=2

-6x+6y=-3

Subtract the second equation from the first equation to eliminate x:

-6x+8y=2

-(-6x+6y=-3) (Here, distribute.)

2y=5, y=2.5

Plugging y in to equation 1 and rearranging:

-3x+4*2.5=1

-3x+10=1

-3x=-9

x=3

So, x=3 and y=2.5.

• Anonymous
9 years ago

Remember what you do to one side of the equation, you have do it on OTHER side also.

Your approach is right but you need to fix one thing. Look at your first step and there is the problem in your evaluation.

Second problem that I see is that you are adding -6 and -6, which doesn't cancel out but adds up to -12. Fix it by either multiplying your first equation by -2 or if you multiply by 2 then SUBTRACT instead of adding the equations.

Hope these guidelines help, I would give away the answer, but I think this would be more helpful.

• Anonymous
9 years ago

You have at least one error. Correctly:

-6x+8y =2 (not 1)

-6x+6y = 3

2y= -1

y= -1/2

Substituting, -3x - 2 = 1

solving, x= -1

• 9 years ago

multiply the first equation by -2 and try again

• Como
Lv 7
9 years ago

6x - 8y = - 2

-6x + 6y = - 3_____ADD

-2y = - 5

y = 5/2

6x = - 2 + 20

6x = 18

x = 3

x = 3 , y = 5/2

• 9 years ago

divide second equation by -2 to get

3x-3y=3/2

then add it to first one

(-3x+4y) + (3x-3y)=(1)+(3/2)

y=5/2

etc.