Question 1121921: xy=nza
if n,z,a are constant what happens to the value of x if y is halved Found 2 solutions by ikleyn, greenestamps:Answer by ikleyn(52803) (Show Source):
Two numbers x and y are multiplied to get a constant, nza.
If one of the two numbers is halved, in order to keep the constant product the other number needs to be doubled.
"Doubling and halving" is a common practice in mental arithmetic. For example, to multiply 12 times 35 you can double the 35 to 70 and halve the 12 to 6 and get 6 times 70. With the trailing 0 in one of the numbers the multiplication is easy:
