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elimination
y=1/2x+1
y=-3x+8
 Jan 27, 2012
 #1
avatar+3088 
0
short answer:
[input]solve( y=1/(2x)+1, y=-3x+8 )[/input]

long answer:
y=1/2x+1
y=-3x+8

1/(2x)+1=-3x+8 |-1
1/(2x) = -3x+7 |*2x
1 = (-3x+7)*2x
1 = -3x*2x+7*2x
1 = -6x^2+14x |-1
-6x^2+14x-1=0
p-q-formula (quadratic formula)
=> {x=0.073760245949667, x=2.259573087383667}

now insert both "x" in one of your equations:
=> {y=1.221280737849, y=7.778719262151}
 Jan 27, 2012
 #2
avatar
0

Multiply top equation by 6, add two equations.

7y = 14

y = 2

 Jan 11, 2016
 #3
avatar+7372 
0

\(y=\frac{1}{2}x+1\\ y= -3x+8\)------(2)------(1)

(1)-(2): 0 = \(\frac{7}{2}x-7\)

        \(\frac{7}{2}x=7\\x=2\)

 

\(y = (\frac{1}{2})(2)+1\\y=1+1\\y=2\)

.
 Jul 7, 2016

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