Question

ДАМ 95 БАЛЛОВ!рещите уравнение БЕЗ ПОДБОРА.МАГАЗИН СО СКЛАДА ПОЛУЧИЛ 1000 ЛИНЕЕК ПО 20 СМ И 30 СМ.ОБЩАЯ ИХ ДЛИНА РАВНА 220 М.СКОЛЬКО 20 САНТИМЕТРОВЫХ ЛИНЕЕК ДРСТАВИЛИ В МАГАЗИН

Answer 1

X- линейки по 0,2м; (1000-x) - линейки по 0,3м; 0,2x+0,3(1000-x)=220; 0,2x-0,3x=220-300; 0,1x=80; x=800 ; 1000-x=1000-800=200; Ответ: 800 линеек по 20см и 200 линеек по 30см.

Answer 2

Пусть х линеек 20см, у линеек 30см. Всего их х+у. По условию 1000.
Их длина 20х+30у. По условию 220м. Составляем систему.
х+у=1000
0,2х+0,3у=220.
х=1000-у, тогда 
0,2(1000-у)+0,3у=220
200-0,2у+0,3у=220
0,1у=220-200
0,1у=20
у=200. 
200 линеек 30см, 800 линеек 20см.

Answer 3

Solving the Equation

To solve the equation without guesswork, we need to set up an equation based on the given information and then solve for the unknown variable. Let's break down the problem step by step.

1. We know that the store received 1000 rulers, with some measuring 20 cm and others measuring 30 cm. 2. The total length of all the rulers is 220 m.

Let's assume that the number of 20 cm rulers is represented by x and the number of 30 cm rulers is represented by y.

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

20x + 30y = 220

Now, we can solve this equation to find the value of x, which represents the number of 20 cm rulers in the store.

To solve the equation, we can use various methods such as substitution, elimination, or graphing. In this case, let's use the substitution method.

We can rearrange the equation to solve for x:

20x = 220 - 30y

Dividing both sides of the equation by 20, we get:

x = (220 - 30y) / 20

Now, we can substitute this expression for x into the original equation:

20 * ((220 - 30y) / 20) + 30y = 220

Simplifying the equation:

220 - 30y + 30y = 220

The 30y terms cancel out, leaving us with:

220 = 220

This equation is true for any value of y. Therefore, there are infinitely many solutions for this equation.

To find the number of 20 cm rulers, x, we can choose any value for y and substitute it back into the equation:

x = (220 - 30y) / 20

For example, if we choose y = 0, the equation becomes:

x = (220 - 30 * 0) / 20 = 220 / 20 = 11

So, if there are no 30 cm rulers in the store, there would be 11 rulers measuring 20 cm.

Please note that the equation has infinitely many solutions, and the number of 20 cm rulers will vary depending on the number of 30 cm rulers in the store.

I hope this helps! Let me know if you have any further questions.