Question

(10b+4)+(6-9b)-(3b-7)+20+(-7+2x)-(-3x-7)

Answer 1

(10b+4)+(6-9b)-(3b-7)=10b+4+6+9b-3b+7
=10b+9b-3b+4+6+7
=16b+17

20+(-7+2x) - (-3x -7)
=20-7+2x+3x+7
=20-7+7+2x+3x
=20+5x

Espero que te sierva!. Saludos!