<span><span>4<span>(<span>x−b</span>)</span></span>=x</span>Step 1: Add -x to both sides.<span><span><span><span>−<span>4b</span></span>+<span>4x</span></span>+<span>−x</span></span>=<span>x+<span>−x</span></span></span><span><span><span>−<span>4b</span></span>+<span>3x</span></span>=0</span>Step 2: Add 4b to both sides.<span><span><span><span>−<span>4b</span></span>+<span>3x</span></span>+<span>4b</span></span>=<span>0+<span>4b</span></span></span><span><span>3x</span>=<span>4b</span></span>Step 3: Divide both sides by 3.<span><span><span>3x/</span>3</span>=<span><span>4b/</span>3</span></span><span>x=<span><span>4/3</span>b</span></span>Answer:<span>x=<span><span>4/3</span><span>b</span></span></span>
The mistake here is that Carlos did not correctly use the distributive property (in fact, he didn't use it at all.) 14(49) 14(40 + 9) Multiply <u>both</u> 40 and 9 by 14, then add them again. 14(40)+14(9) 560+126 686 is the correct answer.