PP1 (Shorter) Quant Section 2 (Medium) Q8

<p><span style="color:#27ae60;"><span style="font-size:20px;">Solving The Problem</span></span></p> <p>We can begin by expanding out the equation. This might help us to cancel some common terms to make it easier for us to solve:</p> <ul> <li>$(2x+1)(x-5)=2(x^2-1)$</li> <li>$2x(x) + 2x(-5) + 1(x) + 1(-5) = 2(x^2) - 2$</li> <li>$2(x^2)-10x+x-5=2(x^2)-2$</li> <li>$2(x^2)-9x-5=2(x^2)-2$</li> </ul> <p>Now the $2(x^2)$ nicely cancels out on both sides, making it much easier to solve:</p> <ul> <li>$2(x^2)-9x-5=2(x^2)-2$</li> <li>$-9x-5=-2$</li> <li>$-9x=3$</li> <li>$x=\frac{3}{-9}$</li> <li>$x =-\frac{1}{3}$</li> </ul> <p>So, the answer would be <span style="color:#27ae60;">A</span>.</p>