Use the left and right triangles. (the two smaller ones -- ACD and BCD)
By similar triangles ACD is similar to BCD
on the left AD/CD is one ratio
On the right CD/DB is the other. These two ratios are equal because they are corresponding parts.
AD / CD = CD / DB
AD = 3
DB = 12
CD = ??
Substitute.
3/CD = CD/12 Cross multiply
36 = CD^2
sqrt(36) = sqrt(CD^2)
CD = 6 <<<<==== Answer.
A <<<<====Answer.
Unusual question. 4/5 = 0.8, which is NOT a repeating decimal; it's a rational fraction.
Two whole numbers whose least common denominator is 36 could be many different pairs: 1 and 36, 2 and 36, 3 and 36, 4 and 36, 4 and 18, 4 and 9, 6 and 36, 9 and 36, 9 and 12, 12 and 36, 12 and 18, 18 and 36, and lastly 36 and 36.
If you want fractions in simplest form, with different denominators, and with an LCD of 36, I would go with 4/5 and 9/13.
I think the reason these work is because 5, 13, and 36 are all pairwise relatively prime (meaning the LCD of any two of them is their product), and because the LCD of 4 and 9 is 36, like I said earlier.
Answer:
that's a
Step-by-step explanation:
y=[x]-3
I think
This expression is a good candidate for "factoring by grouping." I note that the first 2 terms and the last 2 terms share a common factor, 2x+1:
8x^3 + 4x^2 - 18x - 9
4x^2 *(2x + 1) -9 (2x+1)
This can be re-written as (2x+1)(4x2-9)
The latter factor is also easily factorable:
(2x+1)(2x-3)(2x+3) (answer)
