<span>f(x) = x² + 4x
so
</span><span>f(-2) = (-2)² + 4(-2)
f(-2) = 4 - 8
f(-2) = -4
answer
-4</span>
Answer:
We need 540 grams of 0.5% hydrocortisone cream
Step-by-step explanation:
Lets call x the amount of grams needed. This means that the combined cream will have 180+x grams. We want x such that
x * 0.005 + 180*0.025 = (180+x)*0.01
Hence
0.005x + 4.5 = 1,8+0.01x
Lets put the x in the same side and take common factor
4.5-1.8 = 0.01x-0.005x
2.7 = (0.01-0.005)x = 0.005x
As a result
x = 2.7*0.005 = 540
We need 540 grams.
The start time is 9:15 A.M. I believe.
I took away 6 hours from the elapsed time to get 12:00 P.M. (noon). Then, I took away another 3 hours to get 9:00 A.M. Now, we only have 3/4 hour left. 3/4 of 60 is 45. 60 - 45 = 15. Add 15 minutes to 9:00.
Hope it helps,
Loafly
Answer:
7 minutes
Step-by-step explanation:
okay so lets make blocks = x and neighborhood = y
2x + y =10
2x + 4y = 31
multiply the top equation by -1 so we can single out y
-2x - y = -10
2x + 4y = 31
combine the two equations
3y = 21
since the x's have canceled each other out, just divide both sides by 3 to get a single y
y = 7
