Answer:
)x + 5)(x - 5)
Step-by-step explanation:
x² - 25 ← is a difference of squares and factors in general as
a² - b² = (a + b)(a - b), thus
x² - 25 = x² - 5² = (x + 5)(x - 5)
Answer:
so you'll take width (or w) and times it by Height (or h)
50 x 100 = 5000 = example
I hope this helps...
Step-by-step explanation:
Seems to be an arythmetic sequence
Sn=[n(a1+an)]/2
where
Sn means sum of all terms up the nth term
n=number of terms
a1=first term
an=nth term
so from 86 to the 22th term is from a1 to a22
find teh sequence
miknus 7 each time
an=a1+d(n-1)
an=87-7(n-1)
find 22n term
a22=87-7(22-1)
a22=87-7(21)
a22=87-147
a22=-60
S22=[22(87-60)]/2
S22=[22(27)]/2
S22=594/2
S22=297
the sum is 297
50 times 28, you will get 1400.
If trying to mental calculate, I would :
28=20+8
50 times 20 = 1000
50 times 8 = 400
Then add them up to 1400.
vi is going in the positive direction (up). (That's my choice). a (acceleration) is going in the minus direction (down). The directions could be reversed.
Givens
vi = 160 ft/s
vf = 0 (the rocket stops at the maximum height.)
a = - 9.81 m/s
t = ????
Remark
YOu have 4 parameters between the givens and what you want to solve. Only 1 equation will relate those 4. Always always list your givens with these problems so you can pick the right equation.
Equation
a = (vf - vi)/t
Solve
- 32 = (0 - 160)/t Multiply both sides by t
-32 * t = - 160 Divide by -32
t = - 160/-32
t = 5
You will also need to solve for the height to answer part B
t = 5
vi = 160 m/s
a = - 32
d = ???
d = vi*t + 1/2 a t^2
d = 160*5 + 1/2 * - 32 * 5^2
d = 800 - 400
d = 400 feet
Part B
You are at the maximum height. vi is 0 this time because you are starting to descend.
vi = 0
a = 32 m/s^2
d = 400 feet
t = ??
formula
d = vi*t + 1/2 a t^2
400 = 0 + 1/2 * 32 * t^2
400 = 16 * t^2
400/16 = t^2
t^2 = 25
t = 5 sec
The free fall takes the same amount of time to come down as it did to go up. Sort of an amazing result.
