Question

Вычислите: 1) (1/4-2/3)×(4/5-2/15)×(-3/5); 2)(1/6-5/9)×(1/2-3/7)×7 1/5; 3) (5/6-2/3)×(7/8-1/2)×(-4)=СРОЧНО СДЕЛАЙТЕ ПЛИЗ ДАМ 20 БАЛЛОВзаранее спасибо

Answer 1

1. (-5/12)×(2/3)×(-3/5)
(1/12)×2
= 1/6
2. (-1/18)×(1/2)×7 1/5
-7/180
3. 1/6×3/8×(-4)
-1/2×1/2
-1/4=-0.25

Answer 2

Calculation of the Expressions

To calculate the given expressions, let's break them down step by step:

1) Expression 1: - Calculation: (1 + (1/4 - 2/3) × (4/5 - 2/15) × (-3/5)) - Let's simplify the expression inside the parentheses first: - (1/4 - 2/3) = -5/12 - (4/5 - 2/15) = 58/75 - (-3/5) = -3/5 - Now, substitute the simplified values back into the main expression: - (1 + (-5/12) × (58/75) × (-3/5)) - Multiply the fractions: - (-5/12) × (58/75) × (-3/5) = 29/100 - Substitute the result back into the main expression: - (1 + 29/100) - Add the fractions: - 1 + 29/100 = 129/100

Therefore, the value of the first expression is 129/100.

2) Expression 2: - Calculation: ((1/6 - 5/9) × (1/2 - 3/7) × 7 + 1/5) - Let's simplify the expression inside the parentheses first: - (1/6 - 5/9) = -1/18 - (1/2 - 3/7) = 1/14 - Now, substitute the simplified values back into the main expression: - ((-1/18) × (1/14) × 7 + 1/5) - Multiply the fractions: - (-1/18) × (1/14) × 7 = -1/36 - Substitute the result back into the main expression: - (-1/36 + 1/5) - Find a common denominator for the fractions: - (-1/36 + 1/5) = (-5/180 + 36/180) - Add the fractions: - (-5/180 + 36/180) = 31/180

Therefore, the value of the second expression is 31/180.

3) Expression 3: - Calculation: (5/6 - 2/3) × (7/8 - 1/2) × (-4) - Let's simplify the expression inside the parentheses first: - (5/6 - 2/3) = 1/6 - (7/8 - 1/2) = 3/8 - (-4) = -4 - Now, substitute the simplified values back into the main expression: - (1/6 × 3/8 × -4) - Multiply the fractions: - (1/6) × (3/8) × (-4) = -1/4

Therefore, the value of the third expression is -1/4.

Results:

1) Expression 1: 129/100 2) Expression 2: 31/180 3) Expression 3: -1/4

Please note that the values provided above are the results of the calculations based on the given expressions.