Answer:
System of two linear equations can't have exactly two solutions. Reason is that when we have two straight lines,they can only intersect at one point of intersection,no more. Or let's see if lines are equivalent,then they have infinitely many solutions,because any point on line can be solution for the system.
Step-by-step explanation:
Let x be the mass of the paperbacks and y be the mass of the textbook.
20x + 9y = 44.4 ----------- (1)
25x + 10y = 51 -------------(2)
(1) x 10:
200x + 90y = 444 --------(1a)
(2) x 9:
225x + 90y = 459 --------(2a)
(2a) - (1a):
25x = 15
x = 0.6 -------- sub into (1)
20 (0.6) + 9y = 44.4
12 + 9y = 44.4
9y = 44.4 - 12
9y = 32.4
y = 3.6
So the paperback's mass is 0.6 pounds and textbook is 3.6 pounds
Answer:
-232
Step-by-step explanation:
the salt flats have an elevation of 50 feet greater than -282, so add 50 to -282 and you get -232
Answer: 0.701
Step-by-step explanation:
Formula : 
, where 
significance level , 
Population standard deviation, n= sample size.
As per given, n= 22
Critical z- value for 90% confidence level : 
Then,
Hence , error bound (EBM) of the confidence interval with a 90% confidence level= ± 0.701
