There are 40 cats in the ecosystem.
You set 1/5 equal to x/200. Then you cross multiply the fractions to get 5x=200. You divide both terms by 5 to get x, which equals 40.
Volume without holes = 3 x 6 x 11 = 198 cubic inches.
Calculate volume of one hole:
3.14 x 0.5^2 x 3 = 2.355 cubic inches
There are 3 holes: 3 x 2.355 = 7.065
Subtract volume of the holes from the brick:
198 - 7.065 = 190.935 cubic inches.
Rounded to the nearest tenth: 190.9 cubic inches.
Simplifying
2c + 3 = 3c + -4
Reorder the terms:
3 + 2c = 3c + -4
Reorder the terms:
3 + 2c = -4 + 3c
Solving
3 + 2c = -4 + 3c
Solving for variable 'c'.
Move all terms containing c to the left, all other terms to the right.
Add '-3c' to each side of the equation.
3 + 2c + -3c = -4 + 3c + -3c
Combine like terms: 2c + -3c = -1c
3 + -1c = -4 + 3c + -3c
Combine like terms: 3c + -3c = 0
3 + -1c = -4 + 0
3 + -1c = -4
Add '-3' to each side of the equation.
3 + -3 + -1c = -4 + -3
Combine like terms: 3 + -3 = 0
0 + -1c = -4 + -3
-1c = -4 + -3
Combine like terms: -4 + -3 = -7
-1c = -7
Divide each side by '-1'.
c = 7
Simplifying
c = 7