Answer:
450 minutes
Step-by-step explanation:
Given
w = 45000 - 100t
Required
Determine how long it'll take to empty the pool
Being empty means there's no water in the pool.
So, we have to set w to 0 to get the value of t
i.e w = 0
Substitute 0 for w in w = 45000 - 100t
0 = 45000 - 100t
Collect Like Terms
100t = 45000
Divide through by 100.
t = 450
Hence, it'll take 450 minutes to empty the pool
18% of 40 is 7.2
Change the percentage (18%) into a decimal by dividing it over 100:
18/100 = 0.18
Divide 7.2 by the decimal (0.18):
7.2 / 0.18 = 40
Answer:
400 cupcakes
Step-by-step explanation:
So, 340 is 85%. 15% is chocolate.
340/x = 85/100
34000=85x
x=400
Total = 400 cupcakes.
Hope this helps!
Step-by-step explanation:
well, the starting equation and the target format have been given.
let's do the multiplications and compare the target with the starting information.
from there we see what is different or missing.
x² + 14x + 13 = 0
and
(x - p)² = q
x² - 2px + p² = q
x² - 2px + (p² - q) = 0
now let's compare the different parts :
x² = x²
-2px = 14x
-2p = 14
p = -7
p² - q = 13
-7² - q = 13
49 - q = 13
36 - q = 0
q = 36
so, the square (x - p)² = (x + 7)² is completed when
x² + 14x + 49 = 0
but we have only "+ 13". so we need to add 36 to get 49. but we need to do it on both sides, to keep the equation true :
x² + 14x + 13 + 36 = 36
x² + 14x + 49 = 36
(x + 7)² = 36
just as we calculated already above.
and now this can be solved by pulling the square root on both sides (a quadratic equation has always 2 solutions)
x + 7 = ±6
x1 = 6 - 7 = -1
x2 = -6 - 7 = -13
