On a recent survey, 40% of the 900 people surveyed preferred running. How many people preferred running?

550

Explanation:

Well first, you need to solve 40 percent of 900 (which is 360) then subtract it from the main amount (900)

So 900-360

360

Step-by-step explanation:

So we have 40% and 900 people. Before we ask ourselves what is 40 percent of 900, lets ask ourselves what is 10 percent. So 10 percent of 900 would be 90 because you have to move the decimal point 1 unit to the left.        

Now, 40 percent is 4 times the value of 10 percent so 40 percent has to be 360, because 90 times 4 is 360.

Hope this helped, good luck :)

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1

14.3

step-by-step explanation:

add all the numbers together.

9 + 12 + 15 + 16 + 17 + 17 = 86

now, divide 86 by how many numbers we have: 6.

86 / 6 = 14.3