Question

两道道简单的勾股定理题 一道因式分解

Answer 1

c-a=5,b=3√5 a=c-5 a^2+b^2=c^2 (c-5)^2+45=c^2 -10c+70=0 c=7 (y+1)(y^2-1)-(y+1)^3 =(y+1)^2[(y-1)-(y+1)] =-2(y+1)^2