Posted by vero on Wednesday, January 7, 2009 at 5:01pm.
Pick any number that will multiply by one of the equations to give the same number as in the other equation. For example, if we multiply equation 1 by 2 we would have
-10x-8y=-22. Why did I pick 2 as a multiplier. Because it gives me -10x and 10x agrees with the x in equation 2 (the sign is different but that's ok). Then adding equation 1 to equation 2 will eliminate x because -10x+10x = 0x. OK?
-5x-4y=-11
10x=-6-y
line them up - something*x + something*y = something
-5 x - 4 y = -11
10 x + 1 y = -6
we could now multiply the first equation by 2 to make the absolute value of the x coefficient 10 for both -then eliminate x by adding them
or
we could multiply the second by 4 to make the absolute value of the y coefficient 4 for both. then eliminate y by subracting them.
Lets do the second and eliminate y:
-5 x - 4 y = -11
40 x + 4 y = -24
------------------ now add
+35 x +0 y = -35
so
x = 35/35 = -1 now go back and use either equation to find y
y = -10(-1) -6
y = 4
oo......thanks to both of you so much
iwnt help wth reduction formulas
-5x - 4y = -11
10x = -6 - y
For the second equation, move -y to the left side and change sign to positive.
-5x - 4y = -11
10x + y = -6
Now you are either going to eliminate the x's or y's first.
If it is x's, then multiply the first equation by 2.
If it is y's, then multiply the second equation by 4.
I'll PICK THE SECOND EQUATION
4(10x + y) = 4(-6)
40x + 4y = -24
-5x - 4y = -11
40x + 4y = -24
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35x = -35 > divide by 35 on both sides
x = -1
Now solve for y by plugging in x value in either equation.
-5(-1) -4y = -11
5 - 4y = -11
-5 -5
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-4y = -16 > divide by -4 on both sides.
y = 4
Take any three lines K,M and P.Draw as many lines as you can by joining them in pairs..what is the maximum number of different lines as you can draw?