Step-by-step explanation:
length = 2×width + 6
84 = 2×length + 2×width
now using the first in the second equation :
84 = 2×(2×width + 6) + 2×width = 4×width + 12 + 2×width
84 = 6×width + 12
72 = 6×width
width = 12 cm
length = 2×width + 6 = 2×12 + 6 = 24 + 6 = 30 cm
Answer:
Given that,
The number of grams A of a certain radioactive substance present at time, in years
from the present, t is given by the formula

a) To find the initial amount of this substance
At t=0, we get


We know that e^0=1 ( anything to the power zero is 1)
we get,

The initial amount of the substance is 45 grams
b)To find thehalf-life of this substance
To find t when the substance becames half the amount.
A=45/2
Substitute this we get,


Taking natural logarithm on both sides we get,







Half-life of this substance is 154.02
c) To find the amount of substance will be present around in 2500 years
Put t=2500
we get,




The amount of substance will be present around in 2500 years is 0.000585 grams
Answer:
(x , y) ----> (-x , y)
Step-by-step explanation:
(x , y) ----> (-x , y)
Example for 1. :
(-4,2) ---> (4,2)
Given the stated equation we know that that quadratic formula has 2 as its degree. This meats it has 2 roots. A linear equation has a degree of 1. A linear equation has 1 root. To know if they intersect, the must have one root in common. To know this, solve the two equation simultaneously. If they result to an answer then they intersect.