2(a-7)(1-3a) = (2a -14)(1-3a)= -6a^2+42a+2a-14=-6a^2+44a-14
–5(b+4)(–2b-1) = -5(-2b^2-b-8b-4)=10b^2+45b+20
-4(-c-3)(2c – 5) = -4(-2c^2+5c-6c+15)=8c^2+4c-60
2(a-7)(1-3a) = (2a -14)(1-3a)= -6a^2+42a+2a-14=-6a^2+44a-14
–5(b+4)(–2b-1) = -5(-2b^2-b-8b-4)=10b^2+45b+20
-4(-c-3)(2c – 5) = -4(-2c^2+5c-6c+15)=8c^2+4c-60