①(1- × )÷
②21÷( + )÷
③16.1×99+16.1
④64.8÷12.5÷8
⑤37×101
⑥12.5×16×2.5
⑦ -( ÷ + )
⑧51×
⑨36×( + - )
⑩ ÷[( + )× ]
⑪ × + × -
⑫( - )×14×9
① x- x=15
②2x-30%x=13.6
③ + x=
④6x+5×4.4=40
⑤ : =x:
⑥x: = :
⑦1.3:x=52:20
⑧0.6:4=2.4:x