解方程以下几道3/5除（x-0.45）=1/45x-12=3x+121.6x-2/5x+6=100.9*12-3/4x=30.75x-2=1/2x2.4/(x+1/5)=0.2急用!

Question

解方程【以下几道】
3/5除（x-0.45）=1/4 5x-12=3x+12 1.6x-2/5x+6=10 0.9*12-3/4x=3
0.75x-2=1/2x 2.4/(x+1/5)=0.2
急用!

Answer 1

x-0.45=3/5÷1/4=4×3/5=12/5 x=0.45+12/5=45/100+12/5=9/20+12/5=9/20+48/20=57/20=2有17/20
5x-3x=12+12=24 2x=24 x=12 1,6x=16/10x=8/5x 8/5x-2/5x=4 6/5x=4 x=20/6======3又1/3 10.8-3/4x=4 3/4x=10.8-3=7.8 =78/10=39/5 x=39/5÷3/4=52/5=10又2/5
0.75x-0.5x=2 0.25x=2 x=2÷0.25=8 x+1/5=2.4÷0.2=12 x=12-1/5 =11又4/5