Eileen randomly chooses 15 seeds from the bag of flower seeds she has left over from last year, and 10 seeds from the bag she bought this year. which sampling technique did she use to collect the 25 seeds in her sample? a.simple random sampling b.systematic sampling c.convenience sampling d.stratified random sampling

answer:

1/9

step-by-step explanation:

to answer this, we "complete the square."

start with x^2+x.

1. identify the coefficient of the x term; it is 1.

2. halve this result, obtaining 1/2, and then square the latter:   (1/2)² = 1/4

3.   add 1/4 to, and then subtract 1/4 from, the original x^2+x:

      x^2+x + 1/4 - 1/4 this is exactly equivalent to   x^2+x.

4.   strictly speaking, the answer to this problem is 1/4, since adding 1/4 to  

x^2+x makes x^2+x into a perfect square.