You need to isolate/get x by itself in the inequality:
x - 10 < 6 - 5x Add 5x on both sides
x + 5x - 10 < 6 - 5x + 5x
6x - 10 < 6 Add 10 on both sides
6x - 10 + 10 < 6 + 10
6x < 16 Divide 6 on both sides to get x by itself
[tex]x<\frac{16}{6}[/tex] Simplify the fraction
[tex]x<\frac{8}{3}[/tex] So the 1st option