X-5.7=2.15 15 5X-2X=18 3X+0.7=5 3.5×2= 4.2+x 26×1.5= 2x+10 0.5×16―16×0.2=4x 13 9.25－X=0.403 16.9÷X=0.3 X÷0.5=2.6 x＋13＝33 3 － 5x＝80 1.8 +6x＝54 6.7x －60.3＝6.7 9 ＋4x ＝40