The answer of this question is going to be B then on 2 A then D
Answer: the correct answer is ( 7 * 5 ) + (7 * 9 )
Step-by-step explanation:
7 * ( 5+9) = (7 * __) + ( 7 * __) = ( 7 * 5 ) + (7 * 9 )
Answer: f(x) = -0.016x² + 1.6x
Step-by-step explanation:
If the lenght of the road over the arch is 100m, we can consider a coordinate plane and say that the road starts at point (0,0) and finishes at (100,0). The vertice of the parabola is at point (50,40), because the maximum height is 40 and it is always in the middle point of the roots.
So, we have
(0,0) (50,40) (100,0)
A quadratic function is always on the form: f(x) = ax² + bx + c
0 = a0² + b0 + c
40 = a50² + b50 + c
0 = a100² + b100 + c
0 = a0² + b0 + c → c = 0 ∴
40 = a50² + b50
0 = a100² + b100
_________________________
2500a + 50b = 40 (*2)
10000a + 100b = 0
_________________________
5000a + 100b = 80
10000a + 100b = 0 (-)
__________________________
-5000a = 80
-a=80/5000
a=-0.016
∴
2500a + 50b = 40
2500.(-0.016) + 50b = 40
-40 + 50b = 40
50b = 80
b = 80/50
b = 1.6
This way f(x) = -0.016x² + 1.6x
Answer:
8 salt water
7 fresh water
Step-by-step explanation:
Let's represent salt water fish with the variable "s" and fresh water fish with the variable "f".
We can make a system of equations - one equation for the number of fish and the other for the price of the fish.
We know that the total number of fish Laura has is 15, and the total price of the fish was $23.
Solve the system of equations by subtracting the bottom equation from the top equation.
Laura bought 8 salt water fish. Since the total number of fish is 15, the number of fresh water fish must be 7.
Answer:
r = 6
Step-by-step explanation:
Given that M is directly proportional to r³ then the equation relating them is
M = kr³ ← k is the constant of proportionality
To find k use the condition r = 4 when M = 160
k = 
= 
= 2.5, so
M = 2.5r³ ← equation of proportionality
When M = 540, then
540 = 2.5 r³ ( divide both sides by 2.5 )
216 = r³ ( take the cube root of both sides )
r = ![\sqrt[3]{216}](https://tex.z-dn.net/?f=%5Csqrt%5B3%5D%7B216%7D)
= 6
