第1个回答 2013-09-08
2X²+X-1=0
(2x-1)(x+1)=0
x1=1/2,x2=-1.
X²-5=14X
X²-14X-5=0
x=[-b±√(b^2-4ac)]/2a
x1=[14+√(14^2-4×(-5))]/2=7+3√6
x2=[14-√(14^2-4×(-5))]/2=7-3√6
4t²-8t=1
x1=[8+√(8^2-4×4×(-1))]/2×4=(2+√5)/2
x2=[8-√(8^2-4×4×(-1))]/2×4=(2-√5)/2
(x+1)(2x-3)=1
2x²-x-4=0
2(x²-x/2)-4=0
2(x-1/4)²-1/8-4=0
2(x-1/4)²=33/8
(x-1/4)=±(√33)/4
x1=(1+√33)/4
x2=(1-√33)/4本回答被提问者采纳