Question

5) (60a - 30): 5 = 18; 6) 92 + 56 : (14 - b) = 100:7) (C:9) • 15 - 47 = 28;8) (410 – d): 7 + 70 = 120.пжжж​

Answer 1

5) (60а - 30) : 5 = 18

60а - 30 = 18 · 5

60а - 30 = 90

60а = 90 + 30

60а = 120

а = 120 : 60

а = 2

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6) 92 + 56 : (14 - b) = 100

56 : (14 - b) = 100 - 92

56 : (14 - b) = 8

14 - b = 56 : 8

14 - b = 7

b = 14 - 7

b = 7

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7) (c : 9) · 15 - 47 = 28

(с : 9) · 15 = 28 + 47

(с : 9) · 15 = 75

с : 9 = 75 : 15

с : 9 = 5

с = 5 · 9

с = 45

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8) (410 - d) : 7 + 70 = 120

(410 - d) : 7 = 120 - 70

(410 - d) : 7 = 50

410 - d = 50 · 7

410 - d = 350

d = 410 - 350

d = 60

Answer 2

Let's solve each equation step by step:

5. (60a - 30) ÷ 5 = 18

First, simplify the expression inside the parentheses:

60a - 30 = 5 * 18 60a - 30 = 90

Now, isolate the variable "a" by adding 30 to both sides:

60a = 90 + 30 60a = 120

Finally, divide both sides by 60 to find the value of "a":

a = 120 ÷ 60 a = 2

So, the solution for equation 5 is a = 2.

6. 92 + 56 ÷ (14 - b) = 100 ÷ 7

To solve this equation, first simplify the expression inside the parentheses:

92 + 56 ÷ (14 - b) = 14

Now, isolate the term with "b" by subtracting 92 from both sides:

56 ÷ (14 - b) = 14 - 92 56 ÷ (14 - b) = -78

Next, isolate the fraction by multiplying both sides by (14 - b):

56 = -78(14 - b)

Now, divide both sides by -78:

(14 - b) = 56 ÷ -78

Lastly, subtract 14 from both sides to find the value of "b":

b = 14 - (56 ÷ -78) b = 14 - (-0.717948717948718) (rounded to 15 decimal places) b = 14 + 0.717948717948718 b = 14.717948717948718

So, the solution for equation 6 is b ≈ 14.72.

7. (C ÷ 9) • 15 - 47 = 28

First, simplify the expression inside the parentheses:

(C ÷ 9) • 15 - 47 = 28

Next, simplify the expression with the division:

(C / 9) • 15 - 47 = 28

Now, isolate the term with "C" by adding 47 to both sides:

(C / 9) • 15 = 28 + 47 (C / 9) • 15 = 75

Finally, divide both sides by 15 to find the value of "C":

C / 9 = 75 ÷ 15 C / 9 = 5

Now, multiply both sides by 9:

C = 5 * 9 C = 45

So, the solution for equation 7 is C = 45.

8. (410 – d) ÷ 7 + 70 = 120

First, simplify the expression inside the parentheses:

(410 - d) ÷ 7 + 70 = 120

Next, isolate the term with "d" by subtracting 70 from both sides:

(410 - d) ÷ 7 = 120 - 70 (410 - d) ÷ 7 = 50

Now, multiply both sides by 7:

410 - d = 50 * 7 410 - d = 350

Finally, isolate the variable "d" by subtracting 410 from both sides:

d = 410 - 350 d = 60

So, the solution for equation 8 is d = 60.

Summary of solutions:

5. a = 2
6. b ≈ 14.72
7. C = 45
8. d = 60