Question

(y⁴)⁵:(y⁹)²ₓ y³ при y=-1

(z³)⁹:(z⁴)⁶ ₓ z при z=-2

Answer 1

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