Question

А) 7(а+в)^2 /10 + 11(а-в)^2+20в - 5(а^2-в^2) -4в б) 11и+2/7и - 56и+к / 21ик - к-8/3к

Answer 1

Решение внизу на фотке

Answer 2

To simplify the given expressions, let's take them step-by-step.

А) 7(а+в)^2 / 10 + 11(а-в)^2 + 20в - 5(а^2-в^2) - 4в

Step 1: Expand the squared terms. (а + в)^2 = (а + в)(а + в) = а^2 + 2ав + в^2 (а - в)^2 = (а - в)(а - в) = а^2 - 2ав + в^2

Step 2: Simplify the expression. 7(а^2 + 2ав + в^2) / 10 + 11(а^2 - 2ав + в^2) + 20в - 5(а^2 - в^2) - 4в

Step 3: Distribute and combine like terms. (7/10)а^2 + (14/10)ав + (7/10)в^2 + 11а^2 - 22ав + 11в^2 + 20в - 5а^2 + 5в^2 - 4в

Step 4: Combine the like terms. (7/10)а^2 + 11а^2 - 5а^2 + (14/10)ав - 22ав + 20в - 4в + (7/10)в^2 + 11в^2 + 5в^2

Step 5: Further simplify. (7/10)а^2 + 6а^2 - 8ав + 20в + (7/10)в^2 + 16в^2

Step 6: Combine like terms again. (7/10)а^2 + 6а^2 - 8ав + 20в + (7/10 + 16)в^2

Step 7: Simplify the last term. (7/10)а^2 + 6а^2 - 8ав + 20в + (23/10)в^2

So, the simplified expression is:

(7/10)а^2 + 6а^2 - 8ав + 20в + (23/10)в^2

Б) 11и + 2/7и - 56и + к / 21ик - к - 8/3к

Step 1: Combine the like terms. 11и + (2/7)и - 56и + к / 21ик - к - (8/3)к

Step 2: Find a common denominator for the fractions. The common denominator for 7 and 3 is 21.

Step 3: Convert the fractions to have a common denominator of 21. (2/7) = (2/7) * (3/3) = 6/21 (8/3) = (8/3) * (7/7) = 56/21

So the expression becomes:

11и + 6/21и - 56и + к / 21ик - к - 56/21к

Step 4: Combine the like terms. (11 - 56)и + (6/21 - 56/21)к + к / 21ик

Step 5: Simplify the coefficients. -45и - 50/21к + к / 21ик

So, the simplified expression is:

-45и - 50/21к + к / 21ик

Please note that in the second expression, the term "к / 21ик" is left as it is, as it does not have any like terms to combine further.