Three-fourths of the water leaked out of a full aquarium tank. and 15 gallons of water was left. After the leak was fixed, 10 gallons of water was added to the
aquarium tank.
4) How many gallons of water can the aquarium tank hold when it is full?
5) How full was the aquarium tank after the 10 gallons of water was added?
6) How much more water would have to be added to fill the aquarium tank?

4) 60 gallons    5) 25 gallons    6) 35 gallons

Step-by-step explanation:

If three-fourths of the water in the tank leaked out of the full aquarium tank then one-fourths will be left.

so if the leftover was 15 gallons then 1/4 of a number has to equal 15 gallons.

We could represent that by the equation.

1/4 * x = 15

0.25x = 15

x=  60    

4) which means the aquarium tank can hold 60 gallons of water when it is full.

5) If 15 gallons of water was left after the leaking and then they added 10 more gallons of water then 15 + 10 = 25   which means the aquarium was 25 gallon full.

6) If they are 25 gallons in the water now and we need to add some amount of water to get to 60 gallons of water then we will subtract  25 from 60 find how much water needs to be added.

So  60 -25 = 35   which means 35  gallons needs to be added.  

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1

the linear relationship that represents a variation in direct proportion is the linear function that varies according to the numbers of its domain, for example the cost of producing x number of items can be represented in direct proportion by f (x) = mx + b, where m is the constant of proportionality, x the number of articles produced and b the fixed cost