Let
x-----------> the number of kids
y----------> the number of adults
we know that
2.5x+6y=$7150---------> equation 1
x=2y-------------> equation 2
substitute 2 in 1
2.5*[2y]+6y=7150-----> 5y+6y=7150----> 11y=7150-----> y=650
x=2y----> x=2*650----> 1300
the answer is
the number of kids is 1300
{x=-1/3-10/3y
5x+20y=5
5(-1/3-10/3y)+20y=5
solve the equation
.
.
Y=5
substitute the value of y into the equation
x=-1/3-10/3×2
.solve the equation
.
.x=-7
(x,y)=(-7,2)
{3×(-7)+10×2=-1
5x(-7)+28×2=5
simplify
{-1=-1
5=5
the ordered pair is asolution
(X,Y)=(-7,2)
That's all!!!!
You can a linear equation when the line go between the margin and when it have a straight line
85 gallons per day is the unit rate. divide 2550 by 30