Answer:
(negative 7 x + 4)(negative 7 x minus 4)
Step-by-step explanation:
Consider two real numbers a and b. A difference of squares involving a and b is usually given as;
The difference of the two squares above can be factored to yield;
This implies that in order to have the difference of squares we must have a product involving the difference and the sum of the numbers.
The expression;
(negative 7 x + 4)(negative 7 x minus 4) can also be written as ( 4 - 7x) ( -4 - 7x)
( 4 - 7x) ( -4 - 7x) = ( 4 - 7x) (-1( 4 + 7x)) = -1 *( 4 - 7x) ( 4 + 7x)
Expanding the last expression yields;
-1 (16 + 28x -28x - 49x^2) = -1 (16 - 49x^2) = 49x^2 - 16 which is in deed a difference of squares
Step 1:
<span>Calculate the effective thermal conductivity of the wall or ceiling:
</span>
K_eff = [ (13 ÷ 8)(0.12) + (16 - (13 ÷ 8)) × (0.04)] ÷ 16
K_eff =<span> [ 0.195 + 0.565] </span>÷<span> 16
</span>
K_eff = 0.76 ÷ 16
K_eff = 0.0475 W/ (m K)
Step 2:
Calculate <span>the interior ceiling area:
</span>Area of each of the interior side walls = <span>8.82 m x 8.64 m
= 76.2 m</span>²
Area of the interior ceiling = 8.64 m × <span>8.64 m
</span> = 74.6 m²
H = - k·A·(Δ - T) ÷ <span>(thickness)
</span>
H = - 0.0475 ÷ (379.45 × 20) ÷ 45/8
H = - ( - 0.95 × 379.45 ) ÷<span> 0.1429
</span>
H = <span>2.52 kW </span>
Answer: 0.7619
Step-by-step explanation:
Given : Mean : 
Standard deviation : 
Sample size : 
We assume that the variable is normally distributed.
The value of z-score is given by :-
a) For x= 46.9 years
The p-value : 
Hence, the probability that the average age of those doctors is less than 46.9 years =0.7619
Answer: no
Step-by-step explanation: see attachment
