Answer:
20ln(3)
Step-by-step explanation:
Put 15 for A and solve for t.
15 = 45e^(-.05t)
15/45 = 1/3 = e^(-.05t) . . . . divide by 45
ln(1/3) = -.05t . . . . . . . . . . . take natural logs
20ln(3) = t . . . . . . . . . . . . . . multiply by 20, simplify
It will take 20·ln(3) years for the area to decrease to 15 km^2.
ANSWER
The multiplication, CA is defined, and its dimension is 3×2
EXPLANATION
Matrix A is a 2x3 matrix.
Matrix C is a 3×2 matrix.
The product of the two matrices , CA, is defined if and only if the inner product of their dimension are the same.

The inner products are the same.
Hence the matrix multiplication, CA is defined and its dimension is the outer products.

Answer:
1/2 ; 1/4
Step-by-step explanation:
Number of cards in a deck = 52
Number of red cards = 26
Number of spades = 13
Probability of event A :
P(A) = required outcome / Total possible outcomes
P( red card) = number of red cards / total cards in deck
P(red card) = 26 / 52 = 1/2
P(spade) = number of spades / total cards in deck
P(red card) = 13 / 52 = 1 / 4
Answer:
<em>A. 35 deg</em>
Step-by-step explanation:
The triangles are congruent bu HL.
m<RCD = m<PCD = 35 deg