Answer:
49b^2 -36 = (7b -6)(7b +6)
so because there you missed some signs in these wrote choices
hope helped
Step-by-step explanation:
7 because 7•3=21 and if he has as twice much as you 7•2=14 & 14+7=21 books together
<span><span>(<span><span>(<span>−3</span>)</span><span>(2)</span></span>)</span><span>(3)</span></span><span>=<span><span>(<span>−6</span>)</span><span>(3)</span></span></span><span>=<span>−<span>18</span></span></span>