Question

b si c pls hai mate rapid pls

Answer 1

Explicație pas cu pas:

b)

$(x - 1) + (x - 2) + (x - 3) + ... + (x - 20) = 0$

$x + x + ... + x - (1 + 2 + 3 + ... + 20) = 0$

$20x = 1 + 2 + 3 + ... + 20$

$20x = \frac{20 \cdot 21}{2} \implies \bf x = \frac{21}{2}$

c)

$x - 2x + 3x - 4x + ... + 99x - 100x = 500$

$(x - 2x) + (3x - 4x) + ... + (99x - 100x) = 500$

$( - x) + ( - x) + ... + ( - x) = 500$

$- 50x = 500 \implies \bf x = - 10$