Keisha's fish tank has 13 liters of water in it. She plans to add 4 liters per minute until the tank has at least 41 liters. What are the possible numbers of minutes Keisha could add water? Use t for the number of minutes. Write your answer as an inequality solved for t.

7≥t

Step-by-step explanation:

The tank already has 13litres of water in it.

Keisha plans on increasing the quantity of the water to 41 litres. Hence,

41 litres - 13litres = 28litres

The above implies that she needed 28litres to be added to the fish tank.

She adds 4 litres per minute

Now, the question can now be reframed as how many minutes will be needed to add 28litre.

Considering to proportion method

4litres = 1 minute

28litres = t minutes

4litres × t minutes = 28litres

t = 28/4

t = 7 minutes

Hence, at least 7 minutes will be needed to increase the quantity of the tank water from 13litres to 41litres

But since we are to write the answer in an inequality form.

41≥ 13+4t

Solve for t

41≥13+4t

41-13≥4t

28≥4t

Divide both sides by 4

28/4≥4t/4

7≥t

Here are the complex numbers with their simplified differences

(7 -3i) - (6 - 4i) = 1 + i

(4 + 3i) - (6 +2i) = -2 - i

(4 + 5i) - (3 - 4i) = 1 + 9i

(5 + 4i) - (9 + i) = -4 + 3i

A complex number is when a real number and an imaginary number are added together

Complex numbers are usually in the form : a + bi

where a and b are real numbers and i is an imaginary number

for example, in this imaginary number : (7 -3i)

7 and 3 are real numbers while i is the imaginary number

In order to simplify these set of complex numbers, remember that when there is a bracket in mathematics it signifies multiplication.

Here are the set of rules that guide multiplication :

when a negative value is multiplied by a positive value, the value becomes a negative value

For example, -1 x 1 = -1

when a positive value is multiplied by a positive value, the value remains a positive value

For example, 1 x 1 = 1

when a negative value is multiplied by a negative value, the value becomes a negative value

For example,-1 x -1 = 1

Using the above information, the complex numbers can now be simplified

1. (7 -3i) - (6 - 4i)

this above equation becomes :

7 - 3i - 6 + 4i

add like terms together

7 - 6 - 3i + 4i  = 1 + i

2. (4 + 3i) - (6 +2i)

this above equation becomes :

4 + 3i - 6 - 2i

add like terms together

4 - 6 +3i - 2i = -2 - i

3. (4 + 5i) - (3 - 4i)

this above equation becomes :

4 + 5i - 3 + 4i

add like terms together

4 - 3 + 5i + 4i  = 1 + 9i

4. (5 + 4i) - (9 + i)

this above equation becomes :

5 + 4i -9 -i

add like terms together

5 -9 + 4i - i  = -4 + 3i

In order to solve for complex numbers remember that a bracket in mathematics means that a multiplication operation should be carried out. Also, pay cognisance to the rules guiding the multiplication of negative and positive numbers

Here is a similar question and answer on how to solve for complex numbers :