What is 3x+7x=9-18? Math is confusing once you get into 7th grade.

x-(-0.9)

Step-by-step explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation::3*x+7*x-(9-18)=0

Solve::10x+9 = 0

Subtract 9 from both sides of the equation::10x = -9

Divide both sides of the equation by 10::x = -9/10 = -0.900

Step-by-step explanation:

3x+7x=9-18

10x = -9

x = -9 / 10

x = -0.9

 5x + 10y ≥ 60 ⇒ x+2y ≥ 12           (i)  

                x + y ≤ 12                                     (ii)  

Step-by-step explanation:

    Let the hours spent on exercising horse be x

    Let the hours spent on cleaning stalls be y

According to question:

Rob can't work more than 12 hours. So eq. (i) will be x + y ≤ 12

Rob earns $5 an hour by exercising horses and $10 an hour cleaning stalls and he must make $60 . So eq. (ii) will be 5x + 10y ≥ 60.

Dividing eq. (ii) by 5, it will become x + 2y ≥ 12.

∴ system of inequalities are x + y ≤ 12 and x + 2y ≥ 12.