Answer:
Step-by-step explanation:
We can use the process of elimination as
5x + 4y = 24
5(x + 7y = 11) —> 5x + 35y = 55
5x + 4y = 24
-(5x + 35y = 55)
—————————
-31y = -31
-31y/-31 = -31/-31
y=1
x is the number of adults and y is the number of children.
x + y = 12
<span>14x + 10y = 140
lets multiply the first equation by -10 and then add it to the second equation:
-10x - 10y = -120
</span>14x + 10y = <span>140
</span>-----------------------
4x + 0 = 20
x = 20/4
x = 5
then substitute in the original equation:
x + y = <span>12
</span>5 + y = <span>12
</span>y = 12 - 5
y = 7
therefore there were 5 adults and 7 children
Answer:
d
Step-by-step explanation:
The true statement about why the Fibonacci sequence is recursively defined is (c) The Fibonacci sequence is recursively-defined because you must know the values of the two previous terms in order to find the value of the next term
<h3>How to determine the true statement</h3>
With an exception to the first two terms, each term of the Fibonacci sequence is the sum of the two previous terms
This means that,
The Fibonacci sequence cannot be defined explicitly, because the two previous terms can not be determined by a direct formula
Hence, the true statement about why the Fibonacci sequence is recursively defined is (c)
Read more about the Fibonacci sequence at:
brainly.com/question/16934596
Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
