Answer:

Step-by-step explanation:
we have the expression:

To factor this expression we need to indentify the components that are common in both terms.
At first glance there is nothing in common, but we can notice that 30 and 70 are multiples of 10, that is:

so we can substitute this into the expression:

and now that we have the common term (the number 10) we can factorize it, that is, take out the common term and include a parentheses:

Answer:
-f(3x - 1) + 2 = -18x² + 12x + 1
Step-by-step explanation:
Step 1: Find f(3x - 1)
f(3x - 1) = 2(3x - 1)² - 1
f(3x - 1) = 2(9x² - 6x + 1) - 1
f(3x - 1) = 18x² - 12x + 2 - 1
f(3x - 1) = 18x² - 12x + 1
Step 2: Plug in f(3x - 1)
-(18x² - 12x + 1) + 2
Step 3: Evaluate
-18x² + 12x - 1 + 2
-f(3x - 1) + 2 = -18x² + 12x + 1
well, we know that 213.90 includes the 15% gratuity, so if the meal price was say "x", namely that is the 100%, and we add 15% to that, then 100% + 15% = 115%, so 213.90 is really the 115%.
now, if 213.90 is the 115.%, what is "x"? the 100%.

so since we know the meal without the tip is 186 bucks, the tip was then 213.90 - 186 = 27.90.
but they got extra potato wedges with butter and the waitress was wearing her best hat, they added $20 more, so the tip ended up as 27.90 + 20 = 47.90.
now, if the cost of the meal was $186 and that is the 100%, what is 47.90 off of it in percentage?

1.6 × 1.6 × 1.6 × 1.6 = 6.5536