b) Expand and simplify $2 x(3 x-5)+x(x-1)$

Step 1 ：Expand the given expression: \(2x(3x-5)+x(x-1) = 2x(3x) - 2x(5) + x(x) - x(1)\)

Step 2 ：Apply the distributive property: \(6x^2 - 10x + x^2 - x\)

Step 3 ：Combine like terms: \(7x^2 - 11x\)

Step 4 ：\(\boxed{7x^2 - 11x}\)