Hello!
To solve algebraic equation, we will need to use the acronym SADMEP.
SADMEP is similar to PEMDAS, but it is strictly used for solving algebraic equations. Expanded, it is subtract, addition, division, multiplication, exponents, and then parentheses.
Looking at SADMEP, we see that subtract/addition comes first, then division/multiplication, and then exponents/parentheses.
In our equation, our goal is to isolate the variable, "x". Since we have two constants, -3 and 11, and -3 is on the side with the variable, we can add -3 to both sides of the equation first.
Therefore, the first operation needed to solve the equation is addition.
Let n = the unknown number
"The product of a number and 4" = 4 * n = 4n
"increased by 16" = + 16
Set it all equal to - 2.
4n + 16 = - 2
Subtract 16 from both sides to get constants on one side and variables on the other.
4n = - 2 - 16
Combine like terms:
4n = - 18
Divide both sides by 4 to isolate variable n.
n = - 18 / 4
= - 4 and 2/4 = - 4 and 1/2
The answer is 
First, you must divide 12 on both sides.
Then, simplify the fraction.
First, you need to get rid of the fraction by multiplying both sides by 20 and you would get:
4(x + 2) = 5(x + 6)
Now, you need to get rid of the parenthesis by distributing:
4x + 8 = 5x + 30
Subtract both sides by 5x:
-x + 8 = 30
Subtract both sides by 8:
-x = 22
Now, divide both sides by -1:
x = -22
P.S.: You don't really need a calculator to solve.
Answer:
The number of pumps and hours) vary inversely.
The constant of variation is 20.
Step-by-step explanation:
Let x be number of pumps and y be number of hours.
We have been given that working together, two identical water pumps can fill a pull in 10 hours. This means while working alone the pumps will take 2 times as much time to fill the tank.
As we increase number of pumps (x), number of hours (y) is decreasing and as we decrease x our y is increasing, therefore, number of pumps (x) and hours (y) vary inversely.
Since we know that an inversely proportion equation is in form: 
, where, k is constant of variation.
Upon substituting our given values in above equation we will get,
Upon multiplying both sides of our equation by 2 we will get,
Therefore, the constant of variation is 20.
