x^2+y^2=25
y=3x/4
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MathBot Answer:
The system of equations has \(2\) solutions.
\[x = -4, y = -3\]\[x = 4, y = 3\]
Solve \(x^{2} + y^{2} = 25\) for \(x\). \[x = - \sqrt{25 - y^{2}}, x = \sqrt{25 - y^{2}}\]Substitute \(- \sqrt{25 - y^{2}}\) for \(x\) in \(y = \frac{3 x}{4}\) and simplify. $$\begin{aligned}y &= \frac{3 x}{4} \\ y &= \frac{3 \left(- \sqrt{25 - y^{2}}\right)}{4} \\ y &= - \frac{3 \sqrt{25 - y^{2}}}{4} \end{aligned}$$Substitute \(-3\) into \(x^{2} + y^{2} = 25\) to solve for \(x\). $$\begin{aligned}x^{2} + \left(-3\right)^{2} &= 25 \\ x^{2} + 9 &= 25 \\x^{2} - 16 &= 0 \\ \left(x - 4\right) \left(x + 4\right) &= 0 \\ x = -4&, x = 4\end{aligned}$$This yields the following solution. $$\begin{aligned}x = -4,\,y = -3\end{aligned}$$Substitute \(- \sqrt{25 - y^{2}}\) for \(x\) in \(y = \frac{3 x}{4}\) and simplify. $$\begin{aligned}y &= \frac{3 x}{4} \\ y &= \frac{3 \left(- \sqrt{25 - y^{2}}\right)}{4} \\ y &= - \frac{3 \sqrt{25 - y^{2}}}{4} \end{aligned}$$Substitute \(\sqrt{25 - y^{2}}\) for \(x\) in \(y = \frac{3 x}{4}\) and simplify. $$\begin{aligned}y &= \frac{3 x}{4} \\ y &= \frac{3 \left(\sqrt{25 - y^{2}}\right)}{4} \\ y &= \frac{3 \sqrt{25 - y^{2}}}{4} \end{aligned}$$Substitute \(3\) into \(x^{2} + y^{2} = 25\) to solve for \(x\). $$\begin{aligned}x^{2} + 3^{2} &= 25 \\ x^{2} + 9 &= 25 \\x^{2} - 16 &= 0 \\ \left(x - 4\right) \left(x + 4\right) &= 0 \\ x = -4&, x = 4\end{aligned}$$This yields the following solution. $$\begin{aligned}x = 4,\,y = 3\end{aligned}$$