X－ 2/7X=3/4 2X + 2/5= 3/5 4χ－6＝3870%X+ 20%X = 3.6 X×3/5=20×1/4 25%+ 10X = 4/5 X- 15%X = 68 X＋3/8X＝121 5X－3×5/21＝5/7 2/3X÷1/4＝12 6X＋5 =13.4 6X＋5 =13.4 x- 0.8x = 16+6 20 x–8.5= 1.5 X＋25... X－ 2/7X=3/4 2X + 2/5= 3/5 4χ－6＝3870%X+ 20%X = 3.6 X×3/5=20×1/4 25%+ 10X = 4/5 X- 15%X = 68 X＋3/8X＝121 5X－3×5/21＝5/7 2/3X÷1/4＝12 6X＋5 =13.4 6X＋5 =13.4 x- 0.8x = 16+6 20 x–8.5= 1.5 X＋25...