Add <span><span>4<span>a2</span></span><span>4<span>a2</span></span></span>
and <span><span>4<span>a2</span></span><span>4<span>a2</span></span></span>
to get <span><span>8<span>a2</span></span><span>8<span>a2</span></span></span>
.<span><span><span><span>8<span>a2</span></span>+<span>2a</span></span><span>−5</span></span><span><span><span>8<span>a2</span></span>+<span>2a</span></span><span>-<span>5</span></span></span></span>