X-40% X-1 / 2x = 13, It should be x-40% X-1 / 2x = 1 / 13

X-40% X-1 / 2x = 13, It should be 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
Checking calculation: substituting x = 10 / 13 into the original formula, we get:
10/13-40%×10/13-1/2×10/13
=10/13-4/13-5/13
=1/13
(correct)
(... Suffering me ~ ~ hope to adopt, thank you)