Use the definition of absolute value.

The absolute value is always non-negative. So if
is already non-negative,
is unchanged. But if
is negative, then
because multiplying
by -1 makes it positive.
Now, if
, then by the definition of absolute value,

When radicals (square roots) include variables, they are still simplified the same way. We just have to work with variables as well as numbers
1) Factor the radicand (the numbers/variables inside the square root). Factor the number into its prime factors and expand the variable(s).
2) Bring any factor listed twice in the radicand to the outside
Answer:

Step-by-step explanation:
k = 3pw
Step 1: switch sides.
3pw = k
Step 2: Since you want w alone, and w is being multiplied by 3p, divide both sides by 3p.

Answer:Justin plans to spend $20 on sports cards. Regular cards cost $3.50 per pack and foil cards cost $4.50 per pack
number of packs of regular cards =r and the number of packs of foll cards = f
Cost of Regular card = 3.50
Cost of 'r' packs of regular card = 3.50r
Cost of Foil card = 4.50
Cost of 'f' packs of Foil card = 4.50f
Justin plans to spend $20 on sports cards so the sum of cost of regular and Foil cards should be less than or equal to 20
The inequality becomes
3.50r + 4.50f <= 20