Answer:
L=6x^2-4x+5
P=12x^2-4x-2
Step-by-step explanation:
A=WL
So, we know the area is 6x^2-8x-30 and the width is 2x-6
Substitute
(6x^2-8x-30)=(2x-6)(L)
L=(6x^2-8x-30)/(2x-6
Divide
L=6x^2-4x+5
P=2L+2W
Substitute
P=2(6x^2-4x+5)+2(2x-6)
P=12×^2-8x+10+4x-12
Simplify
P=12x^2-4x-2
Answer: 6
explanation:
set up proportions
(4+2)/9 = 4/x
6/9 = 4/x
simplify
2/3 = 4/x
cross multiply
2x = 12
divide
x = 6
Answer:
3
Step-by-step explanation:
9-7=2
2*3=6
6*2=12
75/5=15
15-12=3
Answer:
a) 72.25sec
b) 6.25secs
c) after 10.5secs and 2 secs
Step-by-step explanation:
Given the height reached by the rocket expressed as;
s(t)= -4t^2 + 50t - 84
At maximum height, the velocity of the rocket is zero i.e ds/dt = 0
ds/dt = -8t + 50
0 = -8t + 50
8t = 50
t = 50/8
t = 6.25secs
Hence it will reach the maximum height after 6.25secs
To get the maximum height, you will substitute t - 6.25s into the given expression
s(t)= -4t^2 + 50t - 84
s(6.25) = -4(6.25)^2 + 50(6.25) - 84
s(6.25) = -156.25 + 312.5 - 84
s(6.25) = 72.25feet
Hence the maximum height reached by the rocket is 72.25feet
The rocket will reach the ground when s(t) = 0
Substitute into the expression
s(t)= -4t^2 + 50t - 84
0 = -4t^2 + 50t - 84
4t^2 - 50t + 84 = 0
2t^2 - 25t + 42 = 0
2t^2 - 4t - 21t + 42 = 0
2t(t-2)-21(t-2) = 0
(2t - 21) (t - 2) = 0
2t - 21 = 0 and t - 2 = 0
2t = 21 and t = 2
t = 10.5 and 2
Hence the time the rocket will reach the ground are after 10.5secs and 2 secs
The answer is 156.8. You can do 1.6 times 98
