1.(4ab + 3a) 5b 2.3(4a + 5b -c) 3.4a (a² +5b + 2c -7) 4.7ab (a+b+c-8) 5.(3ab+5a) (a+b) 6.(2a-b) (a+b)

1) (4ab + 3a) 5b
= 20ab² + 15ab

2) 3(4a + 5b - c)
12a + 15b - 3c

3) 4a ( a² + 5b + 2c - 7 )
4a³ + 20ab + 8ac - 28a

4) 7ab ( a + b + c - 8 )
= 7a²b + 7ab² + 7abc - 56ab

5) ( 3ab + 5a ) ( a + b )
= 3a²b + 3ab² + 5a² + 5ab

6) ( 2a - b) ( a + b )
= 2a² - ab + 2ab - b²
= 2a² + ab - b²