`a)(2x+3)²-(2x+1)(2x-1)=22`
`⇔4x²+12x+9-(4x²-1)=22`
`⇔4x²+12x+9-4x²+1=22`
`⇔(4x²-4x²)+12x+(9+1)=22`
`⇔12x+10=22`
`⇔12x=22-10`
`⇔12x=12`
`⇔x=12:12`
`⇔x=1`
Vậy `x=1`
`b)(2x-1)²-2x(2x-3)=5`
`⇔4x²-4x+1-4x²+6x=5`
`⇔(4x²-4x²)+(-4x+6x)+1=5`
`⇔2x+1=5`
`⇔2x=5-1`
`⇔2x=4`
`⇔x=4:2`
`⇔x=2`
Vậy `x=2`
`c)(x-3)²-4=0`
`⇔(x-3)²-2²=0`
`⇔(x-3+2)(x-3-2)=0`
`⇔(x-1)(x-5)=0`
`⇔`$\left[\begin{matrix} x-1=0\\ x-5=0\end{matrix}\right.$
`⇔`$\left[\begin{matrix} x=1\\ x=5\end{matrix}\right.$
Vậy `x∈{1;5}`
`d)(2x-1)²+(x+3)²-5(x+7)(x-7)=0`
`⇔4x²-4x+1+x²+6x+9-5(x²-49)=0`
`⇔4x²-4x+1+x²+6x+9-5x²+245=0`
`⇔(4x²+x²-5x²)+(-4x+6x)+(1+9+245)=0`
`⇔2x+255=0`
`⇔2x=-255`
`⇔x=-255/2`
Vậy `x=-255/2`
`e)25x²-9=0`
`⇔25x²=9`
`⇔x²=9/25`
`⇔x²=(3/5)^2`
`⇔x=±3/5`
Vậy `x∈{3/5;-3/5}`
`f)(x+4)²-(x+1)(x-1)=16`
`⇔x²+8x+16-(x²-1)=16`
`⇔x²+8x+16-x²+1=16`
`⇔(x²-x²)+8x+(16+1)=16`
`⇔8x+17=16`
`⇔8x=16-17`
`⇔8x=-1`
`⇔x=-1/8`
Vậy `x=-1/8`
`g)(2x+1)²-4(x+2)²=9`
`⇔4x²+4x+1-4(x²+4x+4)=9`
`⇔4x²+4x+1-4x²-16x-16=9`
`⇔(4x²-4x²)+(4x-16x)+(1-16)=9`
`⇔-12x-15=9`
`⇔-12x=9+15`
`⇔-12x=24`
`⇔x=24:(-12)`
`⇔x=-2`
Vậy `x=-2`
`h)(3x-1)²+2(x+3)²+11(x+1)(1-x)=6`
`⇔9x²-6x+1+2(x²+6x+9)+11(1-x²)=6`
`⇔9x²-6x+1+2x²+12x+18+11-11x²=6`
`⇔(9x²+2x²-11x²)+(-6x+12x)+(1+18+11)=6`
`⇔6x+30=6`
`⇔6x=6-30`
`⇔6x=-24`
`⇔x=(-24):6`
`⇔x=-4`
Vậy `x=-4`
