Laura brought some fish; salt water ($2 each) and fresh water ($1 each). If she has 15 fish and the total was $23 - how many of each fish did she buy?

8 salt water

7 fresh water

Step-by-step explanation:

Let's represent salt water fish with the variable "s" and fresh water fish with the variable "f".

We can make a system of equations - one equation for the number of fish and the other for the price of the fish.

We know that the total number of fish Laura has is 15, and the total price of the fish was $23.

Solve the system of equations by subtracting the bottom equation from the top equation.

Laura bought 8 salt water fish. Since the total number of fish is 15, the number of fresh water fish must be 7.

8  

7

Step-by-step explanation:

Let the number of fresh water be: - x

Number of salt fishes be 15 - x

x + 2 (15 - x) = 23

x + 30 - 2x = 23

x = 7

Number of fresh water fish bought: -7

Number of salt water fish bought by: -15 -7 = 8

region b will make the inequalities y < 2x + 1 and y > -x - 2 true ⇒ answer a

step-by-step explanation:

* lets study the graph and the inequality to solve the question

- the inequality y > -x - 2

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = -2 that means the line intersect the y-axis at point (0 , -2)

∵ the sign of the inequality is >

∴ we shad the part over the line

  region a and b

- the inequality y < 2x + 1

∵ the form of the inequality is y > mx + c , m is the slope of the line

  and c is the y-intercept (the line intersect y-axis at point (0 , c)

∴ c = 1 that means the line intersect the y-axis at point (0 , 1)

∵ the sign of the inequality is <

∴ we shad the part under the line

  region b and c

∵ the common region between the two lines is region b

∴ region b will make the inequalities y < 2x + 1 and y > -x - 2 true