1)√10*√20+√5*√20-5√8=√200+√100-5√8=√25*8+10-5√8=5√8+10-5√8=10
2)(√mn+n-n+m)/(√m+√n)
(√mn+m)/(√m+√n)=(√m*(√n+√m))/(√m+√n)=√m
X³-xy²= x(x² - y²) = x (x-y)(x+y)
(x+y)² - z² = (x+y - z) (x+y +z)
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