Ask Experts Questions for FREE Help !
Ask
    popsicle100's Avatar
    popsicle100 Posts: 4, Reputation: 1
    New Member
     
    #1

    Nov 18, 2011, 12:42 PM
    Elimination
    3x - 4y = 16
    5x = 6y = 14
    cleopasmwasi's Avatar
    cleopasmwasi Posts: 2, Reputation: 1
    New Member
     
    #2

    Nov 18, 2011, 12:52 PM
    can you please correct your question - how could the second equation have two equal signs?
    popsicle100's Avatar
    popsicle100 Posts: 4, Reputation: 1
    New Member
     
    #3

    Nov 18, 2011, 01:43 PM
    I added an extra = by mistake its

    3x - 4y = 16
    5x + 6y = 14
    Aurora2000's Avatar
    Aurora2000 Posts: 111, Reputation: 16
    Junior Member
     
    #4

    Nov 18, 2011, 02:07 PM
    Multiply by 3 both sides in the first equation, multiply by 2 both sides in the second equation, then sum side by side the 2 equations.

    Alternatively, multiply by 5 both sides in the first equation, multiply by 3 both sides in the second equation, then subtract side by side the 2 equations.
    rpray2007's Avatar
    rpray2007 Posts: 319, Reputation: 23
    Full Member
     
    #5

    Nov 18, 2011, 02:12 PM
    Try to eliminate one variable by multiplying both equations and the subtracting them form each other. This will likely get you one of the variable values. Once that's done, you simply substitute into one of the equations and solving for the remaining variable. So, let's try this

    Let's say you've got these equations:
    (1) 10x - 12y = 24
    (2) 7x + 4y = 48

    My first thought is to find the value of y so I'll try to eliminate x. I'll multiply by 7 for Eq.(1) and 10 for Eq.(2) giving me:
    (1') 70x - 84y = 168
    (2') 70x + 40y = 480

    Now I subtract the two giving me:
    -124y = -312
    I can solve for y
    y = 312/124 (or 2.51612)

    Substituting this in for the above equation (1), I can solve for x now:
    (3) 10x - 12*(312/124) = 24

    (4) 10x = 24 + 12*(312/124)

    x = 5.41935

    You should, of course, double check your work. I'll use Eq. (1):
    10*(5.41935) - 12*2.51612 ~= 24 (rounding error)

    The trick is to find the right numbers to multiply your equations with so they cancel each other out. As you probably noticed, I'm using multiples that will give the same number of x's (or y's) in both equations allowing me to subtract that variable out.

    Good luck.

Not your question? Ask your question View similar questions

 

Question Tools Search this Question
Search this Question:

Advanced Search

Add your answer here.


Check out some similar questions!

Elimination [ 1 Answers ]

-4x-4y=-16 3x+6y=6

Elimination [ 1 Answers ]

3x-24=-4y -2+2y=x

Elimination [ 1 Answers ]

2x-y=7 3x+y=8

Elimination [ 2 Answers ]

Elimination method: a. 3x+4y= -7 b. 2x+3y= -6


View more questions Search