Answer:
0.448 seconds
Step-by-step explanation:
d = -16t² -4t + 412
find t when d = 407
substituting d = 407 into the equation:
407 = -16t² -4t + 412 (subtract 407 from both sides)
-16t² -4t + 412 - 407 = 0
-16t² -4t + 5 = 0 (multiply both sides by -1)
16t² + 4t - 5 = 0
solving using your method of choice (i.e completing the square or using the quadratic equation), you will end up with
t = (-1/8) (1 + √21)= -0.70 seconds (not possible because time cannot be negative)
or
t = (-1/8) (1 -√21) = 0.448 seconds (answer)
The answer is 4 because k+2 would be 2 then times by 6 which is 12 then subtract 8 would be 4
do you some help ?, I can try my best to help
Answer:
SA = 105 in^2
Step-by-step explanation:
To find surface area, find the area of all the shapes and add it all together. This shape has 4 triangle faces. They are all the same. So we can find one of them and times by 4.
Area of a triangle:
A = 1/2b•h
= 1/2• 5 • 8
= 1/2 • 40
= 20
One triangle has area 20, so times by 4 (bc four triangles)
4•20
= 80
Area of square 5•5
= 25
Add the areas:
80 + 25
= 105 sq in
Total cost=$142
cost of parts=$62
cost paid for labour=$142-$62=$80
According to question,
》cost of labour per hr=$32
which can be written as,
》cost of labour/time=$32
Use cross multiplication,
》time=cost of labour/32
Since cost of labour is 80,
Time=80/32
=2.5hrs
