Rafael counted a total of 40 white cars and yellow cars there were 9 times as many white cars as yellow car how many white cars did rafael count

Solution: The number of white cars counted by Rafael is 36.

Explanation:

Let the number of white cars be x and number of yellow cars be y.

It is given that the total number of yellow and white cars counted by rafael is 40.

    .....(1)

According to the given information he counts 9 times as many white cars as yellow car. It means the number of white cars counted by rafael is 9 times of the yellow cars.

       ......(2)

Put   in equation (1).

Put in equation (1).

Since x is the number of white cars, therefore number of white cars counted by Rafael is 36.

White cars did Rafael count = 36 cars

A two-variable linear equation system is an equation that involves 2 variables (the value that can change) and the equation has the highest rank of 1

In this equation system there are coefficients and variables whose solutions can use:

Steps for completion with the substitution method:

       In the statement of the question mentioned Rafael counted the number of white cars and yellow cars = 40 pieces so that the equation:

w + y = 40 ---- equation 1

w = white car

y = yellow car

Then Rafael concluded that white cars were nine times the yellow cars, so the equation was

w = 9y ... equation 2

So that the solution

9y + y = 40

10 y = 40

y = 4

w = 9y

w = 9.4

w = 36

So we get 36 white cars

the substitution method

link

link

The work of a student to solve a set of equations

link

Keywords: the substitution method, elimination, graph, a two-variable linear equation system

idk man good luck man