there were 149 angelfish and goldfish in an aquarium. there were twice as many guppies as angelfish. after selling 35 goldfish there are half as many goldfish as angelfish. how many fish are left in the aquarium

Guppies=2*angels

angels+goldfish=149
goldfish-35=1/2 angels

three equations,three unknowns. I would start with the last two equations, subtract the latter from the second, getting
angles+35=149-1/2 angels
1.5 angels=114
angels=228/3=79
you take if from there...

Let's break down the information step-by-step to find out how many fish are left in the aquarium:

Step 1:
Let's assume the number of angelfish in the aquarium is A.
The number of goldfish in the aquarium is G.
The number of guppies in the aquarium is twice the number of angelfish, so it is 2A.

Step 2:
According to the given information, there were 149 angelfish and goldfish in the aquarium. Therefore, we can write the equation: A + G = 149.

Step 3:
After selling 35 goldfish, the number of goldfish remaining is G - 35.
The number of goldfish remaining is half the number of angelfish, so we can write the equation: G - 35 = 0.5A.

Step 4:
To solve the system of equations, we can substitute the value of G from equation 3 into equation 2:
(0.5A) - 35 + A = 149.
Simplifying the equation, we get: 1.5A - 35 = 149.

Step 5:
Adding 35 to both sides of the equation:
1.5A - 35 + 35 = 149 + 35.
Simplifying further, we get: 1.5A = 184.

Step 6:
Dividing both sides of the equation by 1.5 to solve for A:
(1.5A)/1.5 = 184/1.5.
A = 122.

Step 7:
Substituting the value of A into equation 2 to find the number of goldfish:
G = 149 - A.
G = 149 - 122.
G = 27.

Step 8:
To find the number of guppies, we multiply the number of angelfish by 2:
Number of guppies = 2A = 2 * 122 = 244.

Step 9:
To calculate the total number of fish left in the aquarium, we add the remaining angelfish (A), goldfish (G), and guppies (2A):
Total number of fish = A + G + (2A) = 122 + 27 + 244 = 393.

Therefore, there are 393 fish left in the aquarium.

To find out how many fish are left in the aquarium, we need to solve the problem step by step.

Let's start by assigning variables:
Let A represent the number of angelfish.
Let G represent the number of guppies.
Let F represent the number of goldfish.

From the given information, we know:
A + G + F = 149 -- Equation 1
G = 2A -- Equation 2
F - 35 = 0.5A -- Equation 3

To solve the problem, we need to find the values of A, G, and F.

First, let's substitute Equation 2 into Equation 1:
A + 2A + F = 149
3A + F = 149 -- Equation 4

Next, let's substitute Equation 2 into Equation 3:
F - 35 = 0.5A
F = 0.5A + 35 -- Equation 5

Now, we can substitute Equation 5 into Equation 4:
3A + (0.5A + 35) = 149
3.5A + 35 = 149
3.5A = 149 - 35
3.5A = 114
A = 114 / 3.5
A ≈ 32.57

Since we cannot have a fraction of a fish, we will round A down to the nearest whole number, which gives:
A = 32

Now, using this value, we can find G by substituting it into Equation 2:
G = 2A
G = 2(32)
G = 64

Finally, we can find F by substituting the values of A and G into Equation 1:
A + G + F = 149
32 + 64 + F = 149
96 + F = 149
F = 149 - 96
F = 53

Therefore, there are 32 angelfish, 64 guppies, and 53 goldfish left in the aquarium.