Help on 2 and 3 plz and thank you bless you and god

What constants do you need to add to each of the following quadratic equations to complete the square? 2x2 - 3x = 0 x2 - 8x = 0 2x2 - 11x = 18

Write a polynomial function f of least degree that has rational coefficients, a leading coefficient of 1, and the given zeros. 3, 4+2i, 1+(sqrt)7 the answer is supposed to be: f(x)=x(^5)-13x(^4)+60x(^3)-82x(^2)-144x+360 what am i doing wrong?

Ijust need these 2 questions answered (the second pic is just confirmation i'm not confident in that answer)