-(3A+2)-3(5A+7)

Apply the distributive property.

-(3A)-1⋅2-3(5A+7)

Multiply 3 by -1.

-3A-1⋅2-3(5A+7)

Multiply -1 by 2.

-3A-2-3(5A+7)

Apply the distributive property.

-3A-2-3(5A)-3⋅7

Multiply 5 by -3.

-3A-2-15A-3⋅7

Multiply -3 by 7.

-3A-2-15A-21

-3A-2-15A-21

Subtract 15A from -3A.

-18A-2-21

Subtract 21 from -2.

-18A-23

-18A-23

Simplify -(3A+2)-3(5A+7)