How do you solve #| x - 3 | + 2 >7#?
1 Answer
Apr 17, 2016
Explanation:
The first thing to do here is isolate the modulus on one side of the inequality by subtracting
#|x-3| + color(red)(cancel(color(black)(2))) - color(red)(cancel(color(black)(2))) > 7 - 2#
#|x-3| > 5#
Now, because you're dealing with an absolute value inequality, you must account for two possible cases
#color(purple)(ul(color(black)(x - 3 >= 0 implies |x- 3| = x-3))#
When this is the case, the inequality becomes
#x - 3 > 5#
#x > 8#
#color(purple)(ul(color(black)(x - 3 <0 implies | x -3| = -(x-3)))#
This time, you will have
#-(x-3) > 5#
#-x + 3 >5#
#-x > 2 implies x < -2#
So, you need to have
#color(green)(|bar(ul(color(white)(a/a)color(black)(x in (-oo, -2) uu (8, + oo))color(white)(a/a)|)))#