help me please

[melodym28_99]

use exponents to simplify
-2ccdd=
simplify
7x+5y-2x=
3+x+6x=
9m-3n-4m+10n=
x+9+4(2x-3)=
3x+4+9+x-2x-5=
3a+7b-10b+6c=
3(a+2)+5a=

 

[ting]

-2ccdd = -2c^2d^2

For the others group like terms:

7x +5y -2x= 5x + 5y

Or expand and then group like terms:

x +9 +4(2x -3)= x +9 +8x -12 = 9x - 3

Try the others?