Answer:
(B)
Step-by-step explanation:
Volume of fluid in the tank =1000 gallons
Initial Amount of Salt in the tank, A(0)= 30 pounds
Incoming brine solution of concentration 2 pounds of salt per gallon is pumped in at a rate of 4 gallons per minute.
Rate In=(concentration of salt in inflow)(input rate of brine)

The resulting mixture is pumped out at the same rate, therefore:
Rate Out =(concentration of salt in outflow)(output rate of brine)

Therefore:
The rate of change of amount of salt in the tank,

Hi
Left to do 40% of the shopping
12 items ⇒ 60% of the items
x items ⇒ 40% of the items
60x = 12(40)
60x = 480
x = 480/60
x = 48/6
x = 8 items
Answer:
Left 8 items of the list (40% of the shopping)
Items: 12+8 = 20 items on her list
To find the equation of a line using two given set of points, you must first find slope. To do so, we must use the slope formula:
y2 - y1 / x2 - x1
In this case:
1 - 9 / -1 - 3 = -8 / -4
- 8 / -4 = 2 (simplified)
Now we can use the point-slope formula:
y - y1 = m(x - x1)
y - 1 = 2(x + 1 )
y - 1 = 2x + 2
y = 2x + 3
In order to make 3x - y = 6 in slope intercept form, we must isolate y.
- y = -3x + 6
Note: y cannot be negative, so we'll multiply both sides by -1
( -1 ) - y = - 3x + 6 ( -1 ) = y = 3x -6
Answer:
(D) 
Step-by-step explanation:
Two variables x and y are proportionally related if they can be written in the form y=kx, where k is the constant of proportionality.
From the given options, if 
(B)
is of the form y=kx
(C)
is of the form y=kx with
as
in its lowest form.
(C)
is of the form y=kx with
as
in fractional form.
On the Contrary,
In Option D,
does not represent a proportional relationship between x and y. The constant of proportion is supposed to be a product of x.
Answer:
-0.05
Step-by-step explanation:
Given the expression :
0.1×( – 0.9+ – 0.2÷ – 0.5)
Evaluating the bracket :
0.1 * (-0.9 - 0.2 ÷ - 0.5)
Solving the division first
-0.2 ÷ - 0.5 = 0.4
Now we have ;
0.1 * (-0.9 + 0.4)
0.1 * - 0.5
= - 0.05