Step-by-step explanation:
We have xy = 28, x² + y² = 65 and x³ + y³ = 407.
Since (x + y)(x² - xy + y²) = x³ + y³,
x + y = (x³ + y³)/(x² + y² - xy)
= (407) / [(65) - (28)]
= 407 / 37
= 11.
Hence the sum of the numbers is 11.
N = 3 ( the next number is 3 plus the previous number
sequence formula = an = 3(n-1) +2
so for term the term that =59
59 = 3(n-1) +2
distribute:
59 = 3n -3+2
59 = 3n -1
60 = 3n
n = 60/3
n = 20
59 is the 20th term
this is the answer y=−1/2x+45/2
Answer:
65.2 milliliters
Step-by-step explanation:
The quantity 336 milliliters is the 100% of the solution. We can represent this information on a table:
Milliliters Percentage of solution
336 ⇔ 100%
we are told that 19.4% of this solution is acid, and we need to know how many milliliters represents this percentage. I will call the number of milliliters of acid on the solution 'x', and updating the last table:
Milliliters Percentage of solution
336 ⇔ 100
x ⇔ 19.4%
We can solve this problem for 'x' using the<u> rule of three</u> which is to multiply the cross quantities on the table (336 by 19.4) and then divide by the remaining amount (100):
x = 336(19.4)/100
x = 6,518.4/100
x = 65.184
which rounding to the nearest tenth is: 65.2 milliliters
