SOLUTION: I need help with these graphing problems please 3/7x+5/9y=27 1/9x+2/7y=7 3x-2.5y=7.125 2.5x-3y=7.3125

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Question 179345: I need help with these graphing problems please
3/7x+5/9y=27
1/9x+2/7y=7

3x-2.5y=7.125
2.5x-3y=7.3125

Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
1.%283%2F7%29%2Ax%2B%285%2F9%29%2Ay=27
2.%281%2F9%29%2Ax%2B%282%2F7%29%2Ay=7
Re-arrange both equations to slope-intercept form.
y=mx%2Bb
1.%283%2F7%29%2Ax%2B%285%2F9%29%2Ay=27
1.%285%2F9%29y=-%283%2F7%29%2Ax%2B27
1.y=-%283%2F7%29%289%2F5%29%2Ax%2B27%289%2F5%29
1.y=+-%2827%2F35%29%2Ax%2B%28243%2F5%29+
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2.%281%2F9%29x%2B%282%2F7%29y=7
2.%282%2F7%29y=-%281%2F9%29%2Ax%2B7
2.y=-%281%2F9%29%287%2F2%29%2Ax%2B7%287%2F2%29
2.y=+-%287%2F18%29%2Ax%2B49%2F2+


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If we set the two equations equal to each other, we can solve for the intersection point.
-%287%2F18%29%2Ax%2B49%2F2+=-%2827%2F35%29%2Ax%2B%28243%2F5%29+
%28-%287%2F18%29%2B%2827%2F35%29%29x=243%2F5-49%2F2

%28-%28245%2F630%29%2B%28486%2F630%29%29x=%28243%2F5%29%282%2F2%29-%2849%2F2%29%285%2F5%29
%28241%2F630%29x=%28241%2F10%29
x=%28241%2F10%29%28630%2F241%29=630%2F10
highlight%28+x=63%29
Use eq. 1 or eq. 2, to solve for y,
1.%283%2F7%29%2Ax%2B%285%2F9%29%2Ay=27
%283%2F7%29%2A%2863%29%2B%285%2F9%29%2Ay=27
27%2B%285%2F9%29y=27
highlight%28+y=0%29
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3.3x-2.5y=7.125
4.2.5x-3y=7.3125
Do the same as in the previous case,
3.3x-2.5y=7.125
3.2.5y=3x-7.125
3.y=%283%2F2.5%29x-%287.125%2F2.5%29
3.y=1.2x-2.85
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4.2.5x-3y=7.3125
4.3y=2.5x-7.3125
4.y=%282.5%2F3%29x-%287.3125%2F3%29
4.y=0.833x-2.4375
+graph%28+300%2C+300%2C+-3%2C+3%2C+-5%2C+5%2C+0.833x-2.4375%2C+1.2x-2.85%29+
If we set the two equations equal to each other, we can solve for the intersection point.
0.833x-2.4375=1.2x-2.85+
%280.833-1.2%29x=2.4375-2.85
-0.367x=-.4125
highlight%28x=1.125%29
Use either eq. 3 or eq. 4 to solve for y.
3.y=1.2x-2.85
y=1.2%281.125%29-2.85
y=1.35-2.85
highlight%28y=-1.5%29