Given:
Number of passengers seated in the roller coaster = 21
Empty seats = 3
Number of cars in roller coaster = 4 (each with the same number of seats)
To find:
An equation that can be used to determine the number of seats in each car.
Solution:
Let s be the number of seats in each car.
Total number of seats in 4 cars = 4s
Using the given information,
Total number of seats = Occupied seated + Empty seats
= 21 + 3
= 24
Now, the required equation is

Therefore, the required equation is
.
Divide both sides by 4.


Therefore, the number of seats in each car is 6.
Answer:
b
Step-by-step explanation:
The equation:
3
x
2
−
5
x
−
12
=
0
is in the form:
a
x
2
+
b
x
+
c
=
0
with
a
=
3
,
b
=
−
5
,
c
=
−
12
The roots are given by the quadratic formula:
x
=
−
b
±
√
b
2
−
4
a
c
2
a
x
=
5
±
√
(
−
5
)
2
−
4
(
3
)
(
−
12
)
2
(
3
)
x
=
5
±
√
25
+
144
6
x
=
5
±
√
169
6
x
=
5
±
13
6
That is:
x
=
5
+
13
6
=
18
6
=
3
or
x
=
5
−
13
6
=
−
8
6
=
−
4
3
Answer:
A. 12
Step-by-step explanation:
i= use complicated conjugate to search out definite quantity of 8 + 12i
i = 12i
i= twelve × ei 90°
i = twelve × (cos 90° + i sin 90°)
r = |i| = twelve
determinant: 
(a) 
D<0 means there are no real roots. there are two complex roots with imaginary components.
(b) D=16+20=36>0
D>0 means there are two real roots
(c) D = 20^2-4*4*25 = 0
D=0 means there is one real root with multiplicity 2
Answer:
The number of liters of 25% acid solution = x = 160 liters
The number of liters of 40% acid solution = y = 80 liters
Step-by-step explanation:
Let us represent:
The number of liters of 25% acid solution = x
The number of liters of 40% acid solution = y
Our system of Equations =
x + y = 240 liters....... Equation 1
x = 240 - y
A 25% acid solution must be added to a 40% solution to get 240 liters of 30% acid solution.
25% × x + 40% × y = 240 liters × 30%
0.25x+ 0.4y = 72...... Equation 2
We substitute 240 - y for x in Equation 2
0.25(240 - y)+ 0.4y = 72
60 - 0.25y + 0.4y = 72
Collect like terms
- 0.25y + 0.4y = 72 - 60
0.15y = 12
y = 12/0.15
y = 80 Liters
Solving for x
x = 240 - y
x = 240 liters - 80 Liters
x = 160 liters
Therefore,
The number of liters of 25% acid solution = x = 160 liters
The number of liters of 40% acid solution = y = 80 liters