Question

(1+X)*X=625 该怎么算,

Answer 1

(1+X)*X=625

x²+x=625

(x+1/2)²=1/4+625

(x+1/2)²=2501/4

x+1/2=±√2501/2

所以x1=(-1+√2501)/2 x2=(-1-√2501)/2