a)
\(x+\left(x+2\right)+\left(x+4\right)+...+\left(x+98\right)=0\)
\(x+x+2+x+4+...+x+98=0\)
\(50x+\left(98+2\right).\left[\left(98-2\right):2+1\right]:2=0\)
\(50x+100.49:2=0\)
\(50x+49.50=0\)
\(50x=0-49.50\)
\(50x=-2450\)
\(x=-2450:50\)
\(x=-49\)
b)
\(\left(x-5\right)+\left(x-4\right)+\left(x-3\right)+...+\left(x+11\right)+\left(x+12\right)=99\)
\(x+x+x+...+x-5-4-3-...+11+12=99\)
\(18x+6+7\text{+ 8 + 9 + 10 + 11 + 12 = 99}\)
\(18x+63=99\)
\(18x=99-63\)
\(18x=36\)
\(x=36:18\)
\(x=2\)
a) x + (x + 2) + (x + 4) + ... + (x + 98) = 0
x + x + 2 + x + 4 + ... + x + 98 = 0
50x + (98 + 2).[(98 - 2) : 2 + 1]:2 = 0
50x + 100 .49 : 2 = 0
50x + 49.50 = 0
50x = 0 - 49.50
50x = -2450
x = -2450 : 50
x = -49
b) (x - 5) + (x - 4) + (x - 3) + ... + (x + 11) + (x + 12) = 99
x + x + x + ... + x - 5 - 4 - 3 - ... + 11 + 12 = 99
18x + 6 + 7 + 8 + 9 + 10 + 11 + 12 = 99
18x + 63 = 99
18x = 99 - 63
18x = 36
x = 36 : 18
x = 2
