一除法算式,如除数扩大三倍,则商3余2.如被除数扩大11倍,则商78余9.这个除法算式的正确结果是商几余几
问题描述:
一除法算式,如除数扩大三倍,则商3余2.如被除数扩大11倍,则商78余9.这个除法算式的正确结果是商几余几
答
设被除数,除数位为X,Y
(X-2)/3Y=3...X=9Y+2
(11X-9)/Y=78...11X-9=78Y
代入
11(9Y-2)-9=78Y
..99Y-22-9=78Y
自己看吧,题目好象有问题
答
被除数x 除数y
(x-2)/3y=3 => x-2=9y =>x=9y+2
(11x-9)/y=78 => 11x-9=78y
有上述推的 => 11(9y+2)-9=78y => 99y+22-9-78y=0 => 21y=-13 =>y=-13/21 x=-25/7