Answer:
y = - 10
Step-by-step explanation:
Given that y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 2 when x = - 4, that is
2 = - 4k ( divide both sides by - 4 )
= k, that is
k = -
y = - x ← equation of variation
When x = 20, then
y = - × 20 = - 10
Answer:
a) No. t < 0 is not part of the useful domain of the function
b) 2.0 seconds
Step-by-step explanation:
a) A graph of the function is shown below. It shows t-intercepts at t=-0.25 and t=2.0. We presume that t is measured forward from some event such as the ball being thrown or hit. The model's predicted ball location has no meaning prior to that event, when values of t are negative.
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b) It is convenient to use a graphing calculator to find the t-intercepts. Or, the equation can be solved for h=0 any of several ways algebraically. One is by factoring.
h = 0 = -16t² +28t +8 . . . . . . . . . . . . the ball hits the ground when h = 0
0 = -4(4t² -7t -2) = -4(4t +1)(t -2)
This has t-intercepts where the factors are zero, at t=-1/4 and t=2.
The ball will hit the ground after 2 seconds.
Factor by grouping.
(7x+2)(x-2) I think not sure
Answer:
The cost of each ice cream cone is $4.50
The cost of each ice cream basket is $3.75
The cost of each donut is $1.50
Step-by-step explanation:
Let
x-----> the cost of the ice cream cone
y----> the cost of the ice cream basket
z---> the cost of the donut
we know that
2x+y=12.75 ------> y=12.75-2x ------> equation A
x+2z=7.50 ------> z=(7.50-x)/2 -----> equation B
x+y+z=9.75 ----> equation C
substitute equation A and equation B in equation C and solve for x
x+(12.75-2x)+((7.50-x)/2)=9.75
Multiply by 2 both sides
2x+25.50-4x+7.50-x=19.50
3x=25.50+7.5-19.50
3x=13.5
x=$4.50
Find the value of y
y=12.75-2(4.50)=$3.75
Find the value of z
z=(7.50-4.50)/2=$1.50
therefore
The cost of each ice cream cone is $4.50
The cost of each ice cream basket is $3.75
The cost of each donut is $1.50
Answer:
A. (f + g)(1) = - 9
B. (f - g)(0) = -7
C. (fg)(3) = 0
Step-by-step explanation:
A. (f + g)(1) = f(1) + g(1) f(1) = 1^2 - 9 = 1 - 9 = - 8 g(1) = 1 - 2 = - 1
= -8 -1 = -9
B. (f - g)(0) = f(0) - g(0) f(0) = 0^2 - 9 = 0 - 9 = -9 g(0) = 0 - 2 = -2
= -9 + 2 = -7
C. (fg)(3) = f(3)(g(3) f(3) = 3^2 - 9 = 9 - 9 = 0 g(3) = 3 - 2 = 1
= 0(1) = 0
