2X²-5X-4=0 求配方法解答
问题描述:
2X²-5X-4=0 求配方法解答
答
2x²-5x-4=0
x²-5x/2=2
(x-5/4)²=2+25/16
(x-5/4)²=57/16
x-5/4=±(√57)/4
x1=5/4+(√57)/4 x2=5/4-(√57)/4