①102×0.45
②5.75-0.75×3.2
③17.7÷8÷1.25
④0.99+9.9×9.9
⑤2.5×3.2×1.25
⑥7.2÷0.6+7.2÷0.4
x÷3.6=68
x=
x+2.6=7.8