What are the solutions to the following system?

[tex]\[
\left\{
\begin{aligned}
-2x^2 + y & = -5 \\
y & = -3x^2 + 5
\end{aligned}
\right.
\][/tex]

A. [tex]\((0, 2)\)[/tex]

B. [tex]\((1, -2)\)[/tex]

C. [tex]\((\sqrt{2}, -1)\)[/tex] and [tex]\((- \sqrt{2}, -1)\)[/tex]

D. [tex]\((\sqrt{5}, -10)\)[/tex] and [tex]\((- \sqrt{5}, -10)\)[/tex]



Answer :

To find the solutions to the given system of equations:

[tex]\[ \left\{\begin{aligned} -2x^2 + y &= -5 \\ y &= -3x^2 + 5 \end{aligned}\right. \][/tex]

we will follow a step-by-step approach.

### Step 1: Set the Equations Equal to Each Other

Since both equations equal [tex]\( y \)[/tex], we can set the right-hand sides of the equations equal to each other:

[tex]\[ -2x^2 - 5 = -3x^2 + 5 \][/tex]

### Step 2: Solve for [tex]\( x \)[/tex]

Rearranging the terms to isolate [tex]\( x^2 \)[/tex], we get:

[tex]\[ -2x^2 + 3x^2 = 5 + 5 \][/tex]

[tex]\[ x^2 = 10 \][/tex]

Taking the square root of both sides, we find:

[tex]\[ x = \sqrt{10} \quad \text{or} \quad x = -\sqrt{10} \][/tex]

### Step 3: Substitute [tex]\( x \)[/tex] Back into One of the Original Equations

We can use either of the original equations to find [tex]\( y \)[/tex]. Let's use [tex]\( y = -3x^2 + 5 \)[/tex]:

For [tex]\( x = \sqrt{10} \)[/tex]:

[tex]\[ y = -3(\sqrt{10})^2 + 5 \][/tex]

[tex]\[ y = -3(10) + 5 \][/tex]

[tex]\[ y = -30 + 5 \][/tex]

[tex]\[ y = -25 \][/tex]

So one solution is [tex]\((\sqrt{10}, -25)\)[/tex].

For [tex]\( x = -\sqrt{10} \)[/tex]:

[tex]\[ y = -3(-\sqrt{10})^2 + 5 \][/tex]

[tex]\[ y = -3(10) + 5 \][/tex]

[tex]\[ y = -30 + 5 \][/tex]

[tex]\[ y = -25 \][/tex]

So the other solution is [tex]\((- \sqrt{10}, -25)\)[/tex].

### Conclusions

The solutions to the system of equations are:

[tex]\[ (\sqrt{10}, -25) \quad \text{and} \quad (-\sqrt{10}, -25) \][/tex]

None of the provided options [tex]\((0,2)\)[/tex], [tex]\((1,-2)\)[/tex], [tex]\((\sqrt{2},-1)\)[/tex] and [tex]\((- \sqrt{2},-1)\)[/tex], [tex]\((\sqrt{5}, -10)\)[/tex] and [tex]\((- \sqrt{5}, -10)\)[/tex] match our solutions [tex]\((\sqrt{10}, -25)\)[/tex] and [tex]\((- \sqrt{10}, -25)\)[/tex].