(25 x)2 - 20 x y - (21 y) 2 + 10 Y Z - (z)2. ..///////(...))means an w

1.	(25 x)2 - 20 x y - (21 y) 2 + 10 Y Z - (z)2. ..///////(...))means an whole square
Answer» ANSWER: $\mathrm{\left(25x\right)^2-20xy-\left(21y\right)^2+10yz-z^2=625x^2-20xy-441y^2+10yz-z^2}$ Step-by-step EXPLANATION: $\mathrm{\left(25x\right)^2-20xy-\left(21y\right)^2+10yz-z^2}$ $\mathrm{Apply\:exponent\:rule:\quad \left(a\cdot \:b\right)^n=a^nb^n}$ $\mathrm{=25^2x^2-20xy-\left(21y\right)^2+10yz-z^2}$ $\mathrm{Apply\:exponent\:rule:\quad \left(a\cdot \:b\right)^n=a^nb^n}$ $\mathrm{=25^2x^2-20xy-21^2y^2+10yz-z^2}$ $\mathrm{=625x^2-20xy-441y^2+10yz-z^2}$