✔ 最佳答案
...x.......2
.----- = -----
...3.......x
x^2=6
x=+/-sqrt(6) answer
4x^2+8x-5=0
(2x+5)(2x-1)=0
2x+5=0 2x-1=0
2x=-5 2x=1
x=-5/2 x=1/2 answer
x^2-4x-3=0
a=1 b=-4 c=-3
x=-b+/-sqrt(b^2-4ac)/2a
x=-(-4)+/-sqrt[(-4)^2-4(1)(-3)]/2(1)
x=4+/-sqrt[16+12]/2
x=4+/-sqrt[28]/2
x=4+/-sqrt[4*7]/2
x=4+/-2sqrt(7)/2
.....4+2sqrt(7).......4-2sqrt(7)
x=------------------ , -----------------
.........2.......................2
x=2+sqrt(7), 2-sqrt(7) answer//
....2.............2x
----------- = ------ + 3
..x+1..........2x-3
[ 2/x+1] = 2x/2x-3 +3] (x+1)(2x-3)
2(2x-3)=2x(x+1)+3(x+1)(2x-3)
4x-6=2x^2+2x+3(2x^2-x-3)
4x-6=2x^2+2x+6x^2-3x-9
4x-6=8x^2-x-9
8x^2-x-4x-9+6=0
8x^2-5x-3=0
(x-1)(8x+3)=0
x-1=0 8x+3=0
x=1 8x=-3
x=-3/8 answer