Infinitely many solutions.I will try to solve your system of equations.<span><span><span><span>3x</span>+y</span>=9</span>;<span><span>3x</span>=<span><span>−y</span>+9</span></span></span>Step: Solve<span><span><span>3x</span>+y</span>=9</span>for y:<span><span><span><span>3x</span>+y</span>+<span>−<span>3x</span></span></span>=<span>9+<span>−<span>3x</span></span></span></span>(Add -3x to both sides)<span>y=<span><span>−<span>3x</span></span>+9</span></span>Step: Substitute<span><span>−<span>3x</span></span>+9</span>foryin<span><span><span>3x</span>=<span><span>−y</span>+9</span></span>:</span><span><span>3x</span>=<span><span>−y</span>+9</span></span><span><span>3x</span>=<span><span>−<span>(<span><span>−<span>3x</span></span>+9</span>)</span></span>+9</span></span><span><span>3x</span>=<span>3x</span></span>(Simplify both sides of the equation)<span><span><span>3x</span>+<span>−<span>3x</span></span></span>=<span><span>3x</span>+<span>−<span>3x</span></span></span></span><span>(Add -3x to both sides)
so ur answer is </span><span>Infinitely many solutions.</span><span>
