Given Q = XnYm, `DeltaX` is absolute error in the measurement of X``, `DeltaY` is absolute error in the measurement of Y, then absolute error `DeltaQ` in Q is
`DeltaQ` = `+-``(n(DeltaX)/X + m(DeltaY)/Y)`
`DeltaQ` = `+-` `(n(DeltaX)/X + m(DeltaY)/Y)`Q
`DeltaQ` = `+-` `(n(DeltaX)/X - m(DeltaY)/Y)`Q
`DeltaQ` = `+-` `(n(DeltaX)/Y + m(DeltaY)/X)`Q