Let x be the number.
"twelve decreased by twice a number" ---> 12 - 2x
"8 times the sum of number and 4" ---> 8(x + 4)
12 - 2x = 8(x + 4)
12 - 2x = 8x + 32 (distributive property)
12 = 10x + 32 (add 2x to both sides)
-20 = 10x (subtract 32 from both sides)
x = -2 (divide both sides by 10)
The inverse of subtraction is addition
10(-8s-k)
(10) (-8s + -k)
(10) (-8s) + (10) (-k)
= -80s - 10k
= -10k-80s
Answer:
23 seconds
Step-by-step explanation:
First, find out how many ounces left are needed to fill the water. Subtract the total, 64, by the already filled, 18. This should get you the answer of 46.
Since the dispenser fills 2 ounces per second, you need to divide the number 46 by 2 in order to find the amount of time in seconds it would take to fill the rest of the cup.
Therefore, your answer is 23 seconds.
Hope this helps!