math
posted by Katie A on .
how do I solve using the multiplacation method
2x>1/9

I guess that means that you multiply both sides by the reciprocal of the coefficient thusly:
2x * 1/2 < 1/9 * 1/2
x < 1/18
Have you wondered why multiplying by a negative flips the direction of the inequality? It's just a shorthand way of moving items to the other side.
2x < 4
Now suppose you want +2x: Just add 2x to each side
2x + 2x < 4 + 2x
0 < 4 + 2x
Now subtract 4 from both sides:
4 < 2x
But that's the same as
2x > 4
which is what you get by multiplying by 1 and swapping direction.