Tìm x bt :
a) x + x - 1 + x - 2 +...+z - 50 = 255
b) \(\left(x-\dfrac{1}{3}\right)^2-\dfrac{1}{4}=0\)
c) -2x + 624 = 5y (x,y \(\in\) N )
d) \(\dfrac{x+5}{2}=\dfrac{8}{x+5}\)
e) x + ( x + 1 ) + ( x + 2 ) +...+ ( x + 30 ) =1240
f) ( x - 1 ) + ( x - 2 ) + ... + (x - 19 ) + ( x - 20 ) = -610
g) ( 7x - 11 )3 = ( -3 )2 . 15 + 208
Loga
Toán lớp 6
