I will try to solve your system of equations.<span><span><span> x+y</span>=120</span>;<span><span><span>5.25x</span>+<span>3y</span></span>=517.2</span></span> Step: Solve<span><span>x+y</span>=120</span>for x:<span><span><span> x+y</span>+<span>−y</span></span>=<span>120+<span>−y</span></span></span>(Add -y to both sides)<span>x=<span><span>−y</span>+120</span></span> Step: Substitute<span><span>−y</span>+120</span>forxin<span><span><span><span>5.25x</span>+<span>3y</span></span>=517.2</span>:</span><span><span><span> 5.25x</span>+<span>3y</span></span>=517.2</span><span><span><span>5.25<span>(<span><span>−y</span>+120</span>)</span></span>+<span>3y</span></span>=517.2</span><span><span><span>−<span>2.25y</span></span>+630</span>=517.2</span>(Simplify both sides of the equation)<span><span><span><span>−<span>2.25y</span></span>+630</span>+<span>−630</span></span>=<span>517.2+<span>−630</span></span></span>(Add -630 to both sides)<span><span>−<span>2.25y</span></span>=<span>−112.8</span></span><span><span><span>−<span>2.25y</span></span><span>−2.25</span></span>=<span><span>−112.8</span><span>−2.25</span></span></span>(Divide both sides by -2.25)<span>y=50.133333</span> Step: Substitute50.133333foryin<span><span>x=<span><span>−y</span>+120</span></span>:</span><span> x=<span><span>−y</span>+120</span></span><span>x=<span><span>−50.133333</span>+120</span></span><span>x=69.866667</span>(Simplify both sides of the equation) Answer:<span><span> x=<span><span>69.866667<span> and </span></span>y</span></span>=<span>50.133333</span></span>
