To get a number to decrease by 21% you multiply it by 0.79 (1-0.21)
r = 0.79
Let's solve for y.
<span><span>11−<span><span>12</span>y</span></span>=<span>3+<span>6x
</span></span></span>Step 1: Add -11 to both sides.
<span><span><span><span><span><span>−1/2</span></span>y</span>+11</span>+<span>−11</span></span>=<span><span><span>6x</span>+3</span>+<span>−11
</span></span></span><span><span><span><span>−1</span>2</span>y</span>=<span><span>6x</span>−8
</span></span>Step 2: Divide both sides by (-1)/2.
<span><span><span><span><span>−1/</span>2</span>y</span><span><span>−1/</span>2</span></span>=<span><span><span>6x</span>−8/-1/2
</span></span></span><span>y=<span><span>−<span>12x</span></span>+16</span></span><span>
</span>
