|3x − 6| > 3? I know that you must separate it into two separate inequalities one equaling a positive and one equaling a negative, but would you also change the greater than symbol to a lesser than symbol when you solve the negative?
yes |a|>b then we have a>b a<-b
so you have the two equations 3x-6>3 and 3x-6<-3
ty :)
that and should say or
here is one way to think of it |3x − 6| > 3 if the stuff inside is positive, you can drop the absolute value, 3x - 6 > 3 if the stuff inside is negative, the absolute value does the same thing as multiplying by -1 (-1 times a negative gives you a positive) -1(3x-6) > 3 distribute the -1: -3x + 6 > 3 add 3x to both sides 6 > 3 +3x subtract 3 from both sides 3 > 3x or 3x < 3
should that not say -3x + 6 < 3 @phi?
to quote zzr 3x-6>3 and 3x-6<-3 the last is the same as 3x < 3
I've actually done that in certain situations and it becomes easier. :)
the trick with > or < is always add or subtract from each side that way you don't have to remember to switch the order of the < or > (multiplying by -1 means you have to switch the order of the > or <) so -x > 2 you can multiply by -1 and swap > to < x < -2 or you can add x to both sides 0 > x+2 then add -2 to both sides -2 > x or x < -2 the point is adding gets you the correct > or < on the other hand, remembering the shortcuts is faster...
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