To simplify the expression, we first expand and combine like terms:
(3a + b)(2a - 5b) - 5(a - b)2= 3a(2a) - 3a(5b) + b(2a) - b(5b) - 5(a - b)(a - b)= 6a^2 - 15ab + 2ab - 5b^2 - 5(a^2 - 2ab + b^2)= 6a^2 - 15ab + 2ab - 5b^2 - 5a^2 + 10ab - 5b^2= 6a^2 - 5a^2 - 15ab + 2ab + 10ab - 5b^2 - 5b^2= a^2 - 3ab - 10b^2
Therefore, the simplified expression is a^2 - 3ab - 10b^2.
To simplify the expression, we first expand and combine like terms:
(3a + b)(2a - 5b) - 5(a - b)2
= 3a(2a) - 3a(5b) + b(2a) - b(5b) - 5(a - b)(a - b)
= 6a^2 - 15ab + 2ab - 5b^2 - 5(a^2 - 2ab + b^2)
= 6a^2 - 15ab + 2ab - 5b^2 - 5a^2 + 10ab - 5b^2
= 6a^2 - 5a^2 - 15ab + 2ab + 10ab - 5b^2 - 5b^2
= a^2 - 3ab - 10b^2
Therefore, the simplified expression is a^2 - 3ab - 10b^2.