Answer:
The number of plums = 4
The number of peaches = 16
The number of nectarines = 1
Step-by-step explanation:
Let the number of peaches be = x
Let the number of nectarines be = y
Let the number of plums be = z
A box of fruit has four times more peaches than plums. This means that
The number of peaches = 4 X the number of plums.
i.e x = 4z
The box has 3 fewer nectarines than plums. This means that
Number of nectarines = number of plums - 3
i.e y = z - 3
If the box contains 21 pieces of fruit, this means that if we sum up all the peaches, nectarines, and plums in the box, we will get 21.
Peaches + Nectarines + Plums = 21
4z + z-3 + z = 21
6z =21 +3
z = 24/6
z = 4
Therefore, the number of plums = 4
The number of peaches = 4 X 4 = 16
The number of nectarines = 4 -3 = 1
Elimination:
7x - 3y = 20
5x + 3y = 16
(add)
12x = 36
÷ 12
x = 3
(5 × 3) + 3y = 16
15 + 3y = 16
- 15
3y = 1
÷ 3
y = 1/3
Substitution:
5x + 3y = 16
- 3y
5x = 16 - 3y
÷ 5
x = 3.2 - 0.6y
5(3.2 - 0.6y) + 3y = 16
16 - 3y + 3y = 16
16 = 16
- 16
6y = 0
÷ 6
y = 0
Sorry the substitution messed up for some reason, I'll fix it after I've answered the other question
Answer:
a_n = 2^n + 3
Step-by-step explanation:
The first differences have a geometric progression, so the explicit definition will be an exponential function. (It cannot be modeled by a linear or quadratic function.) The above answer is the only choice that is an exponential function.
__
First differences are ...
(7-5=)2, 4, 8, 16
we have
<u>The system of equations</u>
-------> equation 
-------> equation 
Substitute equation
in equation 

subtract
both sides


Divide by
both sides

the solution is the point 
therefore
the answer is
the solution to the system of equations is the point 
(A) The print area is 4/10 × 100% = 40% of the total, so the ad area is ...
... 100% - 40% = 60% of the print area
(B) News : Ads = (40%) : (60%) = 2 : 3