8√'7-4√'7
To simplify the expression 8√7-4√7, we can combine the like terms, which in this case are the terms with the square root of 7 (√7).
The coefficient of the first term is 8, and the coefficient of the second term is -4. Since these coefficients are like terms, we can combine them to get 8-4 = 4.
Therefore, the simplified expression is 4√7.