Can anybody help me with these math question?

Question

Hey everybody, i need help in solving these problems as of i just don't remember how to do them. If anyone could help me, that would be great!

Simplify each expression:

1) the subtraction of (-x^2 + 3x + 5) from ( 4x^2 - 6x + 2)

2) ( a^2 - b^2 + 5ab) + -3b^2 - 2ab + a^2) =

3) ( -2xy^4) (-3x^4 y^6) =

4) x^2y^2 ( -3xy^3 + 4x^3y^2 - 5x^2y) =

Solve each quadratic equation:

1) 4x^2 + 100 = 0

2) x^2 + 4x = 21

Answer 1

1)

( 4x^2 - 6x + 2) - (-x^2 + 3x + 5) =

4x^2 - 6x + 2 + x^2 - 3x - 5 =

5x^2 - 9x - 3 <==============

2)

( a^2 - b^2 + 5ab) + (-3b^2 - 2ab + a^2) =

a^2 - b^2 + 5ab + -3b^2 - 2ab + a^2 =

2a^2 -2b^2 + 3ab <=============

3)

( -2xy^4) (-3x^4 y^6) =

6x^5 y^10 <=============

4)

x^2y^2 ( -3xy^3 + 4x^3y^2 - 5x^2y) =

(-3x^3 y^5) + (4x^5 y^4) - (5x^4 y^3) <=======

quadratic equations:

1)

4x^2 + 100 = 0

x^2 = -100/4 = -25

x = the square roots of -25

so x has no real roots.<=============

2)

x^2 + 4x = 21

x^2 + 4x -21 = 0

(x+7)(x-3) = 0

either:

x+7 = 0

x = -7

or:

x-3 = 0

x = 3

so x = -7 and 3 <=============

Answer 2

1) - 5x^2 - 3x + 7

2) 2a^2 -4b^2 + 3ab

3) i am not sure sorry

4) sorry still stuck

1) x = +- 5

2) x =