Basic Math/Algebra Absolute Value
I failed algebra last year and now I'm doing an online class.
I forgot how to do these:
8 = |5y+2|
|0.25y+1| = 0.5
You treat what is in the absolute value bracket as a negative and a positive and solve for both. So, pretend that the brackets are parens and put a - in front of one and + in front of the other.
8 = |5y+2| would be
8 = +(5y+2) and 8 = -(5y+2) which equals
8 = 5y+2 and 8 = -5y-2 now solve both for y
6=5y and 10 = -5y
y = 6/5 and y = -2
1>|2-0.8n| to solve inequalities, you change the greater or less than sign to =
1=(2-8/10n) 1= -(2-8/10n)
1=2-8/10n 1= -2+8/10n
-1 = -8/10n 3 = 8/10n
n = 10/8 n = 30/8
Inequalities take an extra step, now you need to determine if the answer is between the 2 solutions or less than and greater than. Pick a number between the two and see if the solution is true
1>|2 - 72/80| False, so try a number greater than 10/8, but less then 30/8
1>|2- 88/80| True statement, so n > 10/8 and less than 30/8, written as 10/8 < n < 30/8
You can check your work by substituting a number greater than 30/8 to confirm that n is between the two.
I'll leave the last one for you to practice on.