Question

(y⁴)⁵:(y⁹)²ₓ y³ при y=-1

(z³)⁹:(z⁴)⁶ ₓ z при z=-2

Answer 1

$(y^4)^5:(y^9)^2cdot y^3=y^{20}:y^{18}cdot y^2=frac{y^{20}cdot y^2}{y^{18}}=frac{y^{22}}{y^{18}}=y^4=(-1)^4=1\\(z^3)^9:(z^4)^6cdot z=z^{27}:z^{24}cdot z=frac{z^{27}cdot z}{z^{24}}=frac{z^{28}}{z^{24}}=z^4=(-2)^4=16$