Question

Dau coroană!!!
$\frac{x - 1}{7} + \frac{x - 2}{7 } + \frac{x - 3}{7} \\+ ... + \frac{x - 99}{7} = 0$
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Answer 1

(x-1)/7+(x-2)/7+...+(x-99)/7 = 0 |•7

(x-1)+(x-2)+...+(x-99) = 0

99x - (1+2+...+99) = 0

99x = 1+2+...+99

99x = 99×100/2

x = 100/2

x = 50