Question

А) -30+20:(-5) Б) 3,9•4,58+3,9•5,42 В) 1 1/11•(1/4+2/3)-1,2

Answer 1

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Answer 2

To solve these expressions, let's go through them one by one:

А) -30 + 20 : (-5)

To solve this, we follow the order of operations (PEMDAS/BODMAS), which stands for Parentheses/Brackets, Exponents/Orders, Multiplication and Division (from left to right), and Addition and Subtraction (from left to right).

1. First, we need to perform the division: 20 / (-5) = -4
2. Now, we can do the addition: -30 + (-4) = -34

So, the result of the expression is -34.

Б) 3.9 • 4.58 + 3.9 • 5.42

Again, we follow the order of operations:

1. Perform the multiplication: 3.9 • 4.58 = 17.862 and 3.9 • 5.42 = 21.138
2. Now, do the addition: 17.862 + 21.138 = 39

So, the result of the expression is 39.

В) 1 1/11 • (1/4 + 2/3) - 1.2

First, let's convert the mixed number into an improper fraction:

1 1/11 = (11 + 1)/11 = 12/11

Now, simplify the expression within the parentheses:

1/4 + 2/3

To add these fractions, we need a common denominator, which is 12:

1/4 = 3/12 2/3 = 8/12

Now, add them: 3/12 + 8/12 = 11/12

Now, the expression becomes:

12/11 • (11/12) - 1.2

Next, perform the multiplication:

12/11 • 11/12 = 1

Now, the expression becomes:

1 - 1.2

Finally, do the subtraction: 1 - 1.2 = -0.2

So, the result of the expression is -0.2.