Question

Артур хочет купить машинки(все они стоят одинаково). Если он купит 7 машин то у него останется 100 рублей, но до покупки 9 машин у него не хватало 20 рублей. Сколько стоит 1 машинка?

Answer 1

1)9-7=2(м)- разница.
2)100-20=80( м)-разница.
3)80:2=40(руб) -стоит 1 машинка .
Ответ :40руб

Answer 2

Calculation of the Cost of One Toy Car

To determine the cost of one toy car, let's analyze the given information.

Arthur wants to buy some toy cars, and all the cars have the same price. If he buys 7 cars, he will have 100 rubles left. However, before buying 9 cars, he was short of 20 rubles.

Let's assume the cost of one toy car is x rubles.

Based on the given information, we can set up the following equations:

Equation 1: 7x + 100 = total amount after buying 7 cars Equation 2: 9x - 20 = total amount before buying 9 cars

To find the cost of one toy car, we need to solve these equations simultaneously.

Solving the Equations

Let's solve the equations using a simple algebraic approach:

Equation 1: 7x + 100 = total amount after buying 7 cars Equation 2: 9x - 20 = total amount before buying 9 cars

To solve Equation 1, we subtract 100 from both sides: 7x = total amount after buying 7 cars - 100

To solve Equation 2, we add 20 to both sides: 9x = total amount before buying 9 cars + 20

Now, we have two equations:

Equation 3: 7x = total amount after buying 7 cars - 100 Equation 4: 9x = total amount before buying 9 cars + 20

Substituting Values

Let's substitute the values from the given information into the equations:

Equation 3: 7x = 100 Equation 4: 9x = 20

Now, we can solve for x by dividing both sides of each equation by the respective coefficients:

Equation 3: x = 100 / 7 Equation 4: x = 20 / 9

Calculating the Cost of One Toy Car

Using a calculator, we can evaluate the values:

x ≈ 14.29 rubles (rounded to two decimal places).

Therefore, the cost of one toy car is approximately 14.29 rubles.

Please note that the exact cost of one toy car may vary depending on the specific pricing and rounding policies of the seller.