Question 474887: When I Evaluate this expression,(-5x)^2= ? if x=4 , What do I do first, get square root of 4 or the product of 4 and then get square root? Do I get sqrt of the product of -5*4 which is -20? or do sqrt x which is ^4=16. Such as -5*16=-80. I then tried it on the calculator and just entered just as written in book with the parenthesis (-5x)^2 x=4 and came up with 400 for the answer, but if I left out the parenthesis the answer was - 80 . That further confused me and I can not find it in my book with parenthesis. Thank you
Answer by richard1234(7193)   (Show Source):
You can put this solution on YOUR website! 80 has nothing to do with it; you do not multiply -5*4*2. The ^2 means you square the expression, so if x is 4, then
(-5x)^2 = (-5*4)^2 = (-20)^2
(-20)^2 = 400, which is the correct answer.
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