Question: What value of c will complete the square below (
) and make the expression a perfect square trinomial?
Answer: c = 225
Step-by-step explanation:
Perfect square trinomials come in the form a² + 2ab + b², which is equal to (a + b)². In the presented trinomial, we can immediately identify that <u>a = x, and b² = c</u>, but we need to find the numerical value of
.
To do this, note that the middle term, or <u>2ab, corresponds with (is equal to) 30x</u>. We know that a = x, and thus, <u>2ab = 2bx</u>. Now, 2bx and 30x are corresponding terms; thus, <u>2bx = 30x</u>.
Dividing by
on both sides gives us <u>b = 15</u>. Therefore, c = b² = 15² = 225. (As a squared binomial, this would be (x + 15)² as a = x and b = 15.)
Answer: 5 (x > 12) or 5 + m(12 - x) (x < 12)
Step-by-step explanation:
flat fee $5 for first x days +
m dolars per day after x days
So, if x > 12, for 12 days the fee is $5 because it is a flat fee that do not depend of the numbers of day.
But, we do not know how many days x is, so
if x < 12, a person will pay, for 12 days, the m times the difference of the days passed x:
5 + m(12-x)
So basically your doing unit rates? Well guess what, I'm studying about that also, and I have a little understanding about unit rates, have you done ratios before?