x-40%x-1/2x=13解方程, 應該是x-40%x-1/2x=1/13
x-40%x-1/2x=1/13
x-2/5x-1/2x=1/13
10/10x-4/10x-5/10x=1/13
1/10x=1/13
x=1/13÷1/10
x=1/13×10
x=10/13
驗算:把x=10/13代入原式得:
10/13-40%×10/13-1/2×10/13
=10/13-4/13-5/13
=1/13
(正確)
(…苦了我啊~~望採納,謝謝)