Question

M × 8,7=50,46 7,511 ÷ а =3,7 8,35 - 1,1 р=7,58 2,32 ÷ х + 2,1=5 5/9 +(х - 2/9)= 2/5 (4,5 - х) × 5,8=8,7 4,8у + 3,7у = 11,9 1)Одно число на 1,4 больше другого, а их сумма равна 27,8. Найти эти числа. 2)На полке стояли книги. Сначала с полки сняли 25% всех книг, а потом 70% оставшихся книг. После чего осталось 27 книг. Сколько книг было на полке первоночально?

Answer 1

Ответ:

Пошаговое объяснение:

m*8,7=50,46  m=50,46:8,7=5,8

7,511:a=3,7  a=7, 511:3,7=2,03

8,35-1,1p=7,58   1,1p=8,35-7,58=0,77  p=0,77:1,1=0,7

2,32:x=5-2,1  2,32x=2,9  2,9:2,32=1,25

5/9+(x-2/9)=2/5  x-2/9=5/9-2/5=7/9  x=7/9:2/9=3 1/2

(4,5-x)*5,8=8,7  4,5-x=8,7-5,8=2,9  4,5-x=2,9  x=4,5-2,9=1,6

4,8y+3,7y=11,9 8,5y=11,9  y=11,9:8,5=1,4

x+(x+1,4)=27,8  2x=1,4=27,8  x=13,2  +13,2+1 4=14,6

Answer 2

Let's solve the two problems step by step:

1. Одно число на 1,4 больше другого, а их сумма равна 27,8. Найти эти числа.

Let's assume the two numbers are x and y. According to the given information:

x = 1.4y (One number is 1.4 times the other) x + y = 27.8 (Their sum is 27.8)

Now, we have a system of two equations with two variables. We can solve it using substitution or elimination method. Let's use substitution:

From the first equation, we can express x in terms of y: x = 1.4y

Now substitute this value of x into the second equation: 1.4y + y = 27.8 2.4y = 27.8

Now, isolate y by dividing both sides by 2.4: y = 27.8 / 2.4 y = 11.583333... (rounded to three decimal places)

Now that we have the value of y, we can find x using the first equation: x = 1.4y x = 1.4 * 11.583333... x = 16.25 (rounded to two decimal places)

So, the two numbers are approximately 16.25 and 11.58.

2. На полке стояли книги. Сначала с полки сняли 25% всех книг, а потом 70% оставшихся книг. После чего осталось 27 книг. Сколько книг было на полке первоначально?

Let's assume the initial number of books on the shelf is x. According to the given information:

After the first removal, 75% of the books are left, which can be expressed as 0.75x. After the second removal, 30% of the remaining books are left (70% removed), which can be expressed as 0.30 * 0.75x = 0.225x.

Now, we are told that 27 books are left after the two removals:

0.225x = 27

To find the initial number of books (x), divide both sides by 0.225:

x = 27 / 0.225 x = 120

So, there were initially 120 books on the shelf.