Упростите выражение1) 2a(5a-7)-5a(3-2a); 2) (2b-3)(4b+9);3) (2c-6)(8c+5)-(5c+2)(5c-2);

Question

Упростите выражение
1) 2a(5a-7)-5a(3-2a);

2) (2b-3)(4b+9);
3) (2c-6)(8c+5)-(5c+2)(5c-2);

Answer 1

1) 2a(5a-7)-5a(3-2a)=10а²-14а-15а+10а²=20а²-29а=а(20а-29)

2) (2b-3)(4b+9)= 8b²+6b-27

3) (2c-6)(8c+5)-(5c+2)(5c-2)=16c²-38c-30- 25c²+4=-9с²-38с-26

Answer 2

1) 2a(5a-7)-5a(3-2a)=10а²-14а-15а+10а²=20а²-29а=а(20а-29)
2) (2b-3)(4b+9)= 8b²+6b-27
3) (2c-6)(8c+5)-(5c+2)(5c-2)=16c²-38c-30- 25c²+4=-9с²-38с-26