Question

1. x2-5x+84 by x+7
2. x2-4 by x+2
3. 15+x-6 by 3x-2
4. 2x3+x2-5x+2 by 2x+3

Answer 1

just consider terms as digits appearing in numerical division dude
multiply 1st term of divisor so that you can get 1st term of your dividend
later multiply the next term of divisor with the same number you multiplied the 1st
after getting a polynomial there,subtract it from your dividend

continue the same pattern till you get the remainder