Tìm x biết:
a, (x+1)+(x+2)+...+(x+199)=0
b, (x=30)+(x-29)+(x-28)=11
c, x+(x-1)+(x-2)+...+(x-100)=0
d, 123-3.(x+4)=23
e, [(14x+26).3+55] : 5 =35
f, 720:[41-(2x-5)]= 23.5
g, (2x-4).(48-12x)2=0
h, (3-x).(4-2x).(x+10)=0
i, |x-7|+13=25
k, |x-3|-16=-4
l, 26-|x+9|=-13
Giúp mk nha!
a, ( x + 1 ) + ( x + 2 ) + ... + ( x + 199 ) = 0
x + 1 + x + 2 + ... + x + 199 = 0
( x + x + ... + x ) + ( 1 + 2 + ... + 199 ) = 0
199x + 19900 = 0
199x = 0 - 19900
199x = -19900
x = -19900 : 199
x = -100
Vậy ...
b, ( x - 30 ) + ( x - 29 ) + ( x - 28 ) = 11
x - 30 + x - 29 + x - 28 = 11
( x + x + x ) - ( 30 + 29 + 28 ) = 11
3x - 87 = 11
3x = 11 + 87
3x = 98
x = \(\frac{98}{3}\)
Vậy ...