X + 15y = 40 / x + 10y = 30 solve for x and y

Use elimination to find both values.
Subtract the second equation from the first equation
x + 15y = 40
- x + 10y = 30
————————
5y = 10
y = 2

Plug in the value for y into one of the equations. I’m going to put it in the second equation.
x + 10(2) = 30
x + 20 = 30
x = 10

x = 10
y = 2

6(2x + 5y)6 (2x) = 12x6 (5y) = 30y12x + 30y

32

step-by-step explanation:

these are your clues: 1. kim ran 18 races2. this was four fewer races than twice thenumber, notice it says twice the number, so you would do the equation 18x2-4; which equals the number 32.thus, 32 is your answer.