1.
a) 16-8x=0
⇔8(2-x)=0
⇔2-x=0
⇔x=2
Vậy S={2}
b) 10+2x=3x-7
⇔-x=-17
⇔x=17
Vậy S={17}
c) 2(-7+3x)=5-(x+2)
⇔-14+6x=5-x-2
⇔7x=17
⇔x=17/7
Vậy S={17/7}
d) -4(x-3)=6x+(x-3)
⇔-4x+12=6x+x-3
⇔-11x=-15
⇔x=15/11
Vậy S={15/11}
2.
a) 3x-2/3-2=4x+1/4
⇔4(3x-2)/12-24/12=3(4x+1)/12
⇔12x-8-24=12x+3
⇔0x=-35 (Vô lí)
Vậy S=∅
b)x-3/4+2x-1/3=2-x/6
⇔3(x-3)/12+4(2x-1)/12=2(2-x)/12
⇔3x-9+8x-4=4-2x
⇔13x=17
⇔x=17/13
Vậy S={17/13}
3.
a)(4-3x)(10x-5)=0
⇔4-3x=0 hoặc 10x-5=0
⇔x=4/3 x=1/2
Vậy S={1/2; 4/3}
b)(x-3)(2x-1)=(2x-1)(2x+3)
⇔(x-3)(2x-1)-(2x-1)(2x+3)=0
⇔(2x-1)(x-3-2x-3)=0
⇔(2x-1)(-x-6)=0
⇔2x-1=0 hoặc -x-6=0
⇔x=1/2 x=-6
Vậy S={-6; 1/2}
c)3x-2x²=0
⇔x(3-2x)=0
⇔x=0 hoặc 3-2x=0
⇔x=0 x=3/2
Vậy S={0; 3/2}
d)(x+7)(3x+1)=49-x²
⇔(x+7)(3x+1)=(7-x)(7+x)
⇔(x+7)(3x+1)-(7-x)(7+x)=0
⇔(x+7)(3x+1-7+x)=0
⇔(x+7)(4x-6)=0
⇔x+7=0 hoặc 4x-6=0
⇔x=-7 x=3/2
Vậy S={-7; 3/2}
Chúc bn hc tốt, cho mk 5 sao và ctlhn nha^^
