tìm x:
a) (2x-1)^2-(x+3)^2=0
b)x^2-x+1/4=0
c)(3x-1)(2x+7)-(x+1)(6x-5)=16
d)x^3-13x=0
e)(4x^4+3x^3):(-x^3)+(15x^2+6x):3x=0
i)2(x+5)-x^2-5x=0
h)4x^2+9x-13=0
g)2(x+5)-x^2-5x=0
tìm x:
a) (2x-1)^2-(x+3)^2=0
b)x^2-x+1/4=0
c)(3x-1)(2x+7)-(x+1)(6x-5)=16
d)x^3-13x=0
e)(4x^4+3x^3):(-x^3)+(15x^2+6x):3x=0
i)2(x+5)-x^2-5x=0
h)4x^2+9x-13=0
g)2(x+5)-x^2-5x=0
Đáp án:
a) (2x-1)^2 – (x+3)^2=0
=> 4x^2 – 4x – 1 – x^2 -6x – 9 = 0
=> 3x^2 – 10x – 10 = 0
=> x=(5+√55) /3.
x=(5-√55) /3
b) x^2 – x + 1/4 =0
=> x=1/2
Giải thích các bước giải:
Giải thích các bước giải:vì:(2x-1)²-(x+3)²=0
=>(2x-1)²=(x+3)²
=>2x-1=x+3=>x=4