<span><span><span><span><span>−12</span><span>a3</span></span><span>b2</span></span>c</span><span><span><span><span>-12</span><span>a3</span></span><span>b2</span></span>c</span></span> out of <span><span><span><span><span><span>−24</span><span>a3</span></span><span>b3</span></span><span>c3</span></span><span><span><span><span>−84</span><span>a4</span></span><span>b2</span></span>c</span></span><span><span><span><span><span>-24</span><span>a3</span></span><span>b3</span></span><span>c3</span></span><span><span><span><span>-84</span><span>a4</span></span><span>b2</span></span>c</span></span></span>.
There are 9 squares, and 4 of them will be painted white, so that means that the remaining squares will be painted black. 9-4=5, so 5 squares will be painted black.
