Giải thích các bước giải:
1.⇔2x-3+5x=4x+12⇔3x=15⇔x=5
2. ⇔5x=15⇔x=3
3. ⇔7t-3=4t+12⇔3t=15⇔t=5
4. ⇔y=-1
5. ⇔27+2x=4x+27⇔2x=0⇔x=0
6.⇔5-6+x=12-8x⇔9x=13⇔x=13/9
7.⇔10x-15-20x+28=19-2x-22⇔-8x=-16⇔x=2
8.⇔2(2x+3)=3(5-4x)⇔4x+6=15-12x⇔16x=9⇔x=9/16
9.⇔9(5x+3)=12(1+2x)⇔3(5x+3)=4(1+2x)⇔15x+9=4+8x⇔7x=-5⇔x=-5/7
10.⇔5(7x-1)=6(16-x)⇔35x-5=96-6x⇔29x=101⇔x=101/29
11. ⇔(x-3)/5=(18-1+2x)/3⇔3(x-3)=5(17+2x)⇔3x-9=85+10x⇔7x=-94⇔x=-94/7
12.⇔(3x-2-30)/6=(3-2x-14)/4⇔2(3x-23)=3(-11-2x)⇔6x-46=-33-6x⇔12x=-79⇔x=-79/12
13.⇔3(3x-7)/6+2(x+1)/6=-16⇔9x-21+2x+2=-16×6⇔11x=-115⇔x=-115/11
14. ⇔[3x-(x+1)]/3=(2x+1)/5⇔5(2x-1)=3(2x+1)⇔10x-5=6x+3⇔4x=8⇔x=2
15. ⇔7(2x-1)/21-3(5x+2)/21=x+13⇔14x-7-15x-6=21(x+13)⇔-x-13=21x+273⇔22x=-286⇔x=-13
