Question

алгебра 7 класс номер:15.15

Answer 1

1 ) 25-5а+5а-а²

2) а²-4а+4а-16

3)с²-7с+7с-49

4)8d-d²+64+8d

5)m²-4m+nm-4n

6)r²-tr+tr-t²

Answer 2

$(5 + a)(5 - a) = 5 ^{2} - a ^{2} \ (a + 4)(a - 4) = a {}^{2} - 4 {}^{2}$