Question

513. Вычислите, применяя переместительное и сочетательное свойства сложения: 1)(5/21+2/15)+2/21;2)(2/35+3/28)+1/28;Решите пожалуйста только этих 2,и сфотографируйте чтоб в ответе фото было,так будет понятней.​

Answer 1

вроде так, надеюсь понятно ( извиняюсь, писала на скорую руку)

Answer 2

Calculation using the Distributive and Associative Properties of Addition

To solve the given expressions using the distributive and associative properties of addition, we will simplify the expressions step by step. Let's solve each expression one by one:

1) (5/21 + 2/15) + 2/21

To simplify this expression, we will first add the fractions within the parentheses:

5/21 + 2/15 = (5 * 15 + 2 * 21) / (21 * 15) = (75 + 42) / 315 = 117 / 315

Now, we can add the result to the fraction outside the parentheses:

(117/315) + 2/21 = (117 * 21 + 2 * 315) / (315 * 21) = (2457 + 630) / 6615 = 3087 / 6615

Therefore, the value of the expression is 3087/6615.

2) (2/35 + 3/28) + 1/28

Similarly, we will start by adding the fractions within the parentheses:

2/35 + 3/28 = (2 * 28 + 3 * 35) / (35 * 28) = (56 + 105) / 980 = 161 / 980

Now, we can add the result to the fraction outside the parentheses:

(161/980) + 1/28 = (161 * 28 + 1 * 980) / (980 * 28) = (4508 + 980) / 27440 = 5488 / 27440

Therefore, the value of the expression is 5488/27440.

Please note that I am unable to provide a photograph in my response. However, you can easily verify the calculations by performing the steps mentioned above.