C^2-6/5C=39/25

问题描述:

C^2-6/5C=39/25

25c^2-30c-39=0
因式分解(5c-13)*(5c+3)=0
c1=13/5
c2=-3/5

C^2-6/5C=39/25
C^2-6/5C+(3/5)²=39/25+(3/5)²
(C-3/5)²=48/25
C-3/5=±(4/5)根号3
C=(3/5)±(4/5)根号3