Question

3 карандаша и 4 ручки стоят 25 рублей; 2карандаша и 2 ручки стоят 14 рублей. Сколько стоит один карандашь?

Answer 1

ручка-р

карандаш-к

3(7-р) +4р = 25 
21 - 3р +4р = 25 
р = 4 
к=3 

Answer 2

Given Information:

- 3 pencils and 4 pens cost 25 rubles. - 2 pencils and 2 pens cost 14 rubles.

Solution:

Let's assume the cost of one pencil is x rubles and the cost of one pen is y rubles.

From the given information, we can create the following equations:

Equation 1: 3x + 4y = 25 Equation 2: 2x + 2y = 14

To find the cost of one pencil, we need to solve these equations.

Let's solve Equation 2 for x: 2x + 2y = 14 2x = 14 - 2y x = (14 - 2y) / 2 x = 7 - y

Substitute this value of x into Equation 1: 3(7 - y) + 4y = 25 21 - 3y + 4y = 25 y = 25 - 21 y = 4

Now, substitute the value of y back into Equation 2 to find x: 2x + 2(4) = 14 2x + 8 = 14 2x = 14 - 8 2x = 6 x = 6 / 2 x = 3

Therefore, the cost of one pencil is 3 rubles.

Answer:

The cost of one pencil is 3 rubles.