Question

(a-10)2 -20(6-a) при a =30/7​

Answer 1

Ответ:

320/7

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Answer 2

Ответ:

а=30/7

$(a - 10)2 - 20(6 - a) = \\ = 2a - 20 - 120 + 20a = \\ \\ 22a - 140 = 2(11a - 70) \\ 22 \times \frac{30}{7} - 140 = \\ 660 \div 7 - 140 = - 45.7$

Answer 3

To find the value of the expression (a-10)² - 20(6-a) when a = 30/7, we substitute the value of a into the expression and simplify.

Let's substitute a = 30/7 into the expression:

((30/7) - 10)² - 20(6 - (30/7))

First, simplify within the parentheses:

(30/7 - 10)² - 20(6 - 30/7)

Next, simplify the subtraction:

(30/7 - 70/7)² - 20(42/7 - 30/7)

Now, simplify further:

(-40/7)² - 20(12/7)

To square a fraction, we square the numerator and the denominator:

(1600/49) - 20(12/7)

Now, multiply 20 by 12/7:

1600/49 - (240/7)

To subtract fractions, we need a common denominator:

1600/49 - (240/7) * (7/7)

1600/49 - 1680/49

Now, subtract the fractions:

(1600 - 1680)/49

-80/49

Therefore, the value of the expression (a-10)² - 20(6-a) when a = 30/7 is -80/49.