Kulay, there is no such thing as a "step by step answer" here. You seem to want a "step by step solution."
I must assume that by 4/5 you actually meant (4/5) and that by 2/3 you meant (2/3). Then your equation becomes:
(4/5)w - 12 = (2/3)w.
The LCD here is 5*3, or 15, so mult. every term by 15:
12w - 180 = 10w.
Add 180 to both sides, obtaining 12 w - 180 + 180 = 10w + 180.
Then 12w = 10w + 180. Simplifying, 2w = 180. What is w?
ANSWER
3) b
EXPLANATION
Given that:

and

Recall that the sine and cosine functions are equal for complementary angles.
This implies that,


Answer:
tax: $18.9
total cost: $333.9
Step-by-step explanation:
$315 × 0.06 = 18.9
18.9 + 315 = 333.9
btw you can also do "315 × 1.06" to get the total cost without having to manually add the tax