That's a lot of points for this question. You don't have to offer that much.
Leading Coefficient: When written in standard form (starting with the variable with the highest power, going to the variable with the next highest power ... all the way down to a number with no variable), the leading coefficient is the number in front of the variable with the highest power.
Let me put this less technically. Find the variable with the highest power. The number in front of that variable is the leading coefficient.
Write this in standard form. 5x^4 -2x + 1 The number in front of the x^4 is the answer. 5 <<<<< answer
18% of 420 is 75.6. Multiply that by 63 to get 4762.8. 420 multiplied by 63 equals 26460. 26460 plus 4762.8 is 31222.8. 31222.8 divided by 63 is 495.6. So the answer is $495.60 per year.