Question

Спростити вираз
           2
(7а+2в)  - (3а-в) (4а+5в)

Answer 1

(7а+2в)²-(3а-в)(4а+5в)=49а²+28ав+4в²-(12а²+15ав-4ав-5в²)=49а²+28ав+4в²-12а²-15ав+4ав+5в²=37а²+9в²+17ав

Answer 2

$(7a+2b)^2-(3a-b)(4a+5b)= \ \ =(49a^2+28ab+4b^2)-(12a^2+15ab-4ab-5b^2)= \ \ =49a^2+28ab+4b^2-12a^2-11ab+5b^2=37a^2+17ab+9b^2$