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1. y = 2x^2 + x - 1

    y = -x - 3

 

2. y = -2x^2 - 2x + 3

    y = 7/2

 Apr 17, 2018
edited by GAMEMASTERX40  Apr 17, 2018

Best Answer 

 #1
avatar+974 
+1

Substituting y = - x - 3 into the first equation, we have: 

 

- x - 3 = 2 x ^ 2 + x -1 

 

Simplifying, we have: 

 

2 x ^ 2 + 2 x + 2 = 0

 

x=-\frac{1}{2}+i\frac{\sqrt{3}}{2},\:x=-\frac{1}{2}-i\frac{\sqrt{3}}{2}

 

Substituting y = 7/2 into the first equation, we have: 

 

7/2  = - 2 x ^ 2 - 2 x + 3

 

Simplifying, we have: 

 

2 x ^ 2 + 2 x + 2 = 0

 

x=-\frac{1}{2}

 

Since you already know one value, you can plug it in to figure out the other variable. 

 Apr 17, 2018
 #1
avatar+974 
+1
Best Answer

Substituting y = - x - 3 into the first equation, we have: 

 

- x - 3 = 2 x ^ 2 + x -1 

 

Simplifying, we have: 

 

2 x ^ 2 + 2 x + 2 = 0

 

x=-\frac{1}{2}+i\frac{\sqrt{3}}{2},\:x=-\frac{1}{2}-i\frac{\sqrt{3}}{2}

 

Substituting y = 7/2 into the first equation, we have: 

 

7/2  = - 2 x ^ 2 - 2 x + 3

 

Simplifying, we have: 

 

2 x ^ 2 + 2 x + 2 = 0

 

x=-\frac{1}{2}

 

Since you already know one value, you can plug it in to figure out the other variable. 

GYanggg Apr 17, 2018

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