When 18 is subtracted from the square of a number, the result is 3 times the number. find the negative solution

x = -3

Step-by-step explanation:

Let the number be "x"

"When 18 is subtracted from square of a number" can be written as :

3 times the number, can be written as:

So we equate and write:

We rearrange and solve by factoring:

x is 6

x is -3

The negative solution is:

x = -3

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15