My son has a maths question:
Simplify 5x * 3/10y
Can anyone help?
Thanks
Typically, simplifying means collecting all like terms and, in the case of fractions [rational functions], reducing so that there is no common multiple for the numerator and denominator. So, let's do an example:
7 x * 4/(12 y )
First look at the numerator [top part]. In order to make removing common multiples easier, writ this as a product of its factors:
7 x * 4 = 2 * 2 * 7 * x
Now the denominator [bottom part] and do the same thing
12 y = 2 * 2 * 3 * y.
We see that the common numbers and variables between the numerator and denominator is 2 * 2 so we can cancel these for both and write
7 x * 4/(12 y ) = (7 * x) / (3 * y) = 7x/(3y)
Depending on the teacher, this is as far as you need to go. If you need to go further than that, you should ask your teacher just what form is wanted.
Notice the parens around the 3y. That's because if we write 7x/3y, the standard way to interpret 7x/3y is
7 * (x/3) * y
which is generally quite different than 7x/(3y).
