126-?÷25×28.7=12.5求问号数字.
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126-?÷25×28.7=12.5求问号数字.
如题.
如题.
![126-?÷25×28.7=12.5求问号数字.](/uploads/image/z/19721799-63-9.jpg?t=126-%3F%C3%B725%C3%9728.7%EF%BC%9D12.5%E6%B1%82%E9%97%AE%E5%8F%B7%E6%95%B0%E5%AD%97.)
先乘除,后加减
126 - A ÷ 25 × 28.7 = 12.5
126 - (A ÷ 25 × 28.7) = 12.5 [先乘除,刮起来成为一体]
126 - 12.5 = (A ÷ 25) × 28.7 [等式左右互换,加变减,乘变除]
113.5 = (A ÷ 25) × 28.7
113.5 ÷ 28.7 = A ÷ 25
113.5 / 28.7 = A / 25
(113.5 x 25) / 28.7 = A
A = 28375/287 = 98又 249/287 = 98.86759581881533
126 - A ÷ 25 × 28.7 = 12.5
126 - (A ÷ 25 × 28.7) = 12.5 [先乘除,刮起来成为一体]
126 - 12.5 = (A ÷ 25) × 28.7 [等式左右互换,加变减,乘变除]
113.5 = (A ÷ 25) × 28.7
113.5 ÷ 28.7 = A ÷ 25
113.5 / 28.7 = A / 25
(113.5 x 25) / 28.7 = A
A = 28375/287 = 98又 249/287 = 98.86759581881533