$(x+\sqrt{5})^{2}$

$(x-\sqrt{5})^{2}$ 

$(x+\sqrt{5})(x-\sqrt{5})$

$(x+5)(x-1)$

I only

II only

I and II

Neither I nor II

$s=42r-t$

$s=7(6r-t)$

$s=\frac{6}{7}r-t$

$s=\frac{6r-t}{7}$

$\frac{1}{2}$

$\frac{5}{2}$

$\frac{9}{2}$

$\frac{11}{2}$

0

16

40

76