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Solve the following system of equations and show all work. y = −x2 + 4 y = 2x + 1

User Paqmo
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Answer:

The solutions to the given system of equations are:

  • x = 1, y = 3
  • x = -3, y = -5

Explanation:

Given system of equations:


\begin{cases}y=-x^2+4\\y=2x+1\end{cases}

To solve the given system of equations, substitute the second equation into the first equation:


\implies 2x+1=-x^2+4

Add x² to both sides:


\implies x^2+2x+1=4

Subtract 4 from both sides:


\implies x^2+2x-3=0

Factor the quadratic equation:


\implies x^2+3x-x-3=0


\implies x(x+3)-1(x+3)=0


\implies (x-1)(x+3)=0

Apply the zero product property:


(x-1)=0 \implies x=1


(x+3)=0 \implies x=-3

Substitute the found values of x into the second equation and solve for y:


x=1 \implies y=2(1)+1=3


x=-3 \implies y=2(-3)+1=-5

Therefore, the solutions to the given system of equations are:

  • x = 1, y = 3
  • x = -3, y = -5
User Dan Snyder
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