Question

(а-3)(3+а)+а(7-а) даю 20 балоооов

Answer 1

Ответ:

Объяснение:

а) 3а+3(7-а) =3а+3*7-3а=21;

б) 4а-2*(8-2а) =4а-2*8+2*2а=8а-16

Answer 2

To find the value of the expression (а-3)(3+а)+а(7-а), we need to perform the given operations and simplify the expression:

(а-3)(3+а)+а(7-а)

Step 1: Distribute the terms in the first bracket (а-3)(3+а):

= а(3+а) - 3(3+а)

Step 2: Distribute the terms in the second bracket а(3+а):

= 3а + а² - 3(3+а)

Step 3: Distribute -3 into (3+а):

= 3а + а² - 9 - 3а

Step 4: Simplify the expression by canceling out the like terms (3а and -3а):

= а² - 9

Now, the expression (а-3)(3+а)+а(7-а) simplifies to а² - 9.

Since no value of а was given, we cannot determine the exact numerical result. However, if you have a specific value for а, you can substitute it into the expression to find the corresponding result.