Answer:
Step-by-step explanation:
Given a sample M(t)
M(t) = 120 • ( 81 / 625)^t
When is the fraction of the mass decay to 3/5 of it's mass
Generally
M(t) = Mo•(k^t)
The original mass is 120
Mo = 120
So, we want to find time when it decay to 3/5 of it's original mas
M = 3/5 × 120
M = 72
Then,
M(t) = 120 • ( 81 / 625)^t
72 = 120 • ( 81 / 625)^t
72 / 120 = ( 81 / 625)^t
0.6 = ( 81 / 625)^t
Take natural logarithmic of both sides
In(0.6) = In(81/625)^t
In(0.6) = t•In(81/625)
t = In(0.6) / In(81/625)
t = In(0.6) / In(0.1296)
t = 0.25 monthly
t = ¼ monthly
Answer:
2
Step-by-step explanation:
5x+3x=14+2
8x=16
x=2
...
Given
She paid $3 to rent shoes and $ 4.75 for each game of bowling.
she spend a total of $42
How many games did shakira bowl.
To proof
let the number of games shakira did bowl = x
paid $3 to rent shoes and $ 4.75 for each game of bowling
she spend a total = $42
Than the equation is become in the form
4.75x = 42 - 3
4.75 x = 39
x = 8.21(approx)
therefore 8 games did shakira bowl.
Hence proved
3x - 4y = 7
-4y = -3x + 7
y = 3/4x - 7/4.....the slope here is 3/4. A parallel line will have the same slope.
y - y1 = m(x - x1)
slope(m) = 3/4
(-4,-2)....x1 = -4 and y1 = -2
now we sub
y - (-2) = 3/4(x - (-4) =
y + 2 = 3/4(x + 4) <=== this is one
y + 2 = 3/4(x + 4)
y + 2 = 3/4x + 3
y = 3/4x + 3 - 2
y = 3/4x + 1
-3/4x + y = 1
3x - 4y = -4 <==== this is one