<span>=<span><span><span><span><span>(<span>−a</span>)</span><span>(b)</span></span>+<span>8a</span></span>−5</span>+<span><span>−1</span><span>(<span><span><span>(<span>−<span>8a</span></span>)</span><span>(b)</span></span>−4</span>) </span></span></span></span><span>=<span><span><span><span><span><span><span>(<span>−a</span>)</span><span>(b)</span></span>+<span>8a</span></span>+</span>−5</span>+<span><span>−1</span><span>(<span><span>(<span>−<span>8a</span></span>)</span><span>(b)</span></span>)</span></span></span>+<span><span>(<span>−1</span>)</span><span>(<span>−4</span>) </span></span></span></span><span>=<span><span><span><span><span><span><span>(<span>−a</span>)</span><span>(b)</span></span>+<span>8a</span></span>+</span>−5</span>+<span><span>8a</span>b</span></span>+4</span></span><span>=<span><span><span><span><span><span>−<span>ab</span></span>+<span>8a</span></span>+</span>−5</span>+<span><span>8a</span>b</span></span>+4 </span></span> Then after all of that
Combine Like Terms:<span>=<span><span><span><span><span>−<span>ab</span></span>+<span>8a</span></span>+<span>−5</span></span>+<span><span>8a</span>b</span></span>+4 </span></span><span>=<span><span><span>(<span><span>−<span>ab</span></span>+<span><span>8a</span>b</span></span>)</span>+<span>(<span>8a</span>)</span></span>+<span>(<span><span>−5</span>+4</span>)
So now your answer is </span></span></span><span>=<span><span><span><span>7a</span>b</span>+<span>8a</span></span>+<span>−<span>1</span></span></span></span>
