math
posted by kay .
if i cross multiply 1/2*4/22 what will i get.... just really need an example

You can't crossmultiply two fractions. It doesn't mean anything. You crossmultiply when you have an equation with fractions, as in
2/3 = 8/12
Then you multiply the left by thr rightside denominator, and viceversa:
2*12 = 3*8
24 = 24
It's a handy way of getting rid of fractions. What you are really doing is putting everything all over a common denominator, without keeping it around.
2/3 = 8/12
LCD = 36, so
2*12/3*12 = 8*3/12*3
24/36 = 24/36
and you just toss the 36 away, since it no longer affects anything. If two fractions with the same denominator have equal numerators, then they are equal.
If you just want to multiply fractions, your question about
1/2 * 4/22 = (1*4)/(2*22) = 4/44 = 1/11
or, since 1/2 of 4 is 2,
1/2 * 4/22 = 2/22 = 1/11