From the sum of `3x^2-5x+2` and `-5x^2-8x+9` subtract `4x^2-7x+9.`

From the sum of 3x+2x^2-y^2 and 6y-5y^2+3x^2+4x , subtract the sum of x^2-2y^2+3x-5y and 3x^2+2y^2-4x-y

From the sum of 5x-3x^2+y^2 and 8x-3y^2-x^2+x subtract the sum of 2x^2+y^2+4x-2y and x^2+y^2-3x-2y

From the sum of 4x^4-3x^3+6x^2,\ 4x^3+4x-3 and -3x^4-5x^2+2x subtract 5x^4-7x^3-3x+4.

From the sum of x^2+3y^2-6x y ,2x^2-y^2+8x y , y^2+8 and x^2-3x y\ subtract -3x^2+4y^2-x y+x-y+3.

Write each of the following statement by using appropriate grouping symbols: The sum of a-b and 3a-2b+5 is subtracted from 4a+2b-7. Three times the sum of 2x+y-{5-(x-3y)} and 7x-4y+3 is subtracted from 3x-4y+7. The subtraction of x^2-y^2+4x y from 2x^2+y^2-3x y is added to 9x^2-3y^2-x ydot

Subtract the sum of x^2+2x+2 and xy^2+3 from the sum of 2x^2+5x-1 and y^2+x^2y-3

Subtract the sum of 2x-x^2+5\ a n d-4x-3+7x^2from\ 5.

Subtract 6x^(3) -5x^(2)+4x-3 from the sum x+2x^(2)-3x^(3) and 2-x^(2)+6x-x^(3) .

Subtract 12x + 3y - z from the sum of 7x + 4y - 5z + 5 and 6x - 7z - 8 .

Prove that 2cosx. Cos 3x- 2cos 5x. Cos 7x- cos 4x + cos12x=0 .