Answer:
x(3y - 1) and (2a - 3)(2a + 3)
Step-by-step explanation:
(1)
3xy - x ← factor out x from each term
= x(3y - 1)
(2)
4a² - 9 ← is a difference of squares and factors in general as
a² - b² = (a - b)(a + b) , then
4a² - 9
= (2a)² - 3²
= (2a - 3)(2a + 3)
Suppose:
C=cost
c=cost per kilo-watt hour
w=number of watts
h=number of hours
thus
C=kwhc
where:
k=constant of proportionality:
k=C/(whc)
but
C=15 when w=6000, h=10/60=1/6 hours, c=7.5 cents per kw/h
thus
k=15/(6000*1/6*7.5)
k=0.002
thus:
C=0.002(whc)
hence:
when
h=70*2=140=140/6=70/3 hours the cost will be:
C=0.002(6000*70/3*7.5)
C=2100 cents
C=$21
Answer: the equivalent equation is found by distributing the 1/4 to get 4+3x=28
the first step is subtract 4 to both sides
the second step is divide both sides by 3
the answer is x=8
Step-by-step explanation:
Answer:
Part a) The area of the swimming pool is 
Part b) The total area of the swimming pool and the playground is 
Step-by-step explanation:
Part a) Find the area of the swimming pool
we know that
The area of the swimming pool is

where
L is the length side
W is the width side
we have

substitute the values


therefore
The area of the swimming pool is 
Part b) The area of the playground is one and a half times that of the swimming pool. Find the total area of the swimming pool and the playground
we know that
To obtain the area of the playground multiply the area of the swimming pool by one and a half

To obtain the total area of the swimming pool and the playground, adds the area of the swimming pool and the area of the playground
so

therefore
The total area of the swimming pool and the playground is 