Jonathan counted a total of 40 white cars and
yellow cars. There were 9
times as many white cars
as yellow cars. How
many white cars did
Jonathan count?
Create a bar model and
solve.

36 White cars

Step-by-step explanation:

total of 40 white cars and yellow cars"      means     40 = W + Y

 "9 times as many white cars as yellow cars"   means  9Y = W

   9W + 9Y = 360        (first equation; multiply (W+Y=40) by 9 to eliminate Y)

   W   - 9Y  = 0           (carefully revise the second equation)

    (Elimination method:  add the equations)

   10W      = 360

      W  =  36       Ans:  36 White cars

Checking (very important):

   40 = W + Y

   40 = 36 + Y

   4 = Y

 is    9(4) = 36

        36 = 36

step-by-step explanation :

we know that

the measurement of the outer angle is the semi-difference of the arcs which comprises

in this problem

m< xzy is the outer angle

substitute the values

the measure of angle xoy is equal to

> by central angle

substitute the value