Question Number 79719 by Ell Tee last updated on 27/Jan/20
$$\frac{\left(\mathrm{2}.\mathrm{39}\overset{\mathrm{2}} {\right)}−\left(\mathrm{1}.\mathrm{61}\overset{\mathrm{2}} {\right)}}{\mathrm{2}.\mathrm{39}−\mathrm{1}.\mathrm{61}}...? \\ $$$$ \\ $$
Commented by MJS last updated on 27/Jan/20
$$\frac{{a}^{\mathrm{2}} −{b}^{\mathrm{2}} }{{a}−{b}}=\frac{\left({a}−{b}\right)\left({a}+{b}\right)}{{a}−{b}}={a}+{b} \\ $$
Answered by naka3546 last updated on 27/Jan/20
$$\mathrm{4} \\ $$