Solve for x and y, if :

$\Big(\sqrt{27}\Big)^x \div 3^{y+4} = 1$ and

$8^{{4}-\dfrac{x}{3}}- 16^y = 0$

If a = -1 and b = 2, find :

(i) $a^b + b^a$

(ii) $a^b - b^a$

(iii) $a^b \times b^a$

(iv) $a^b \div b^a$

Find the value of : log₅ 625

Find the value of : log₂ 0.125