Respuesta:
7x-(-7x)= 7x+7x= 14x
8x-(-3x)= 8x+3x= 11x
-4x-(-9x)= -4x+9x= 5x
-6x-(-5x)= -6x+5x= -x
13A-(-2x) 145-(21) = 13A+2x+144-21=13A+2x+123
8x-(-27)153-14= 8x+27×153-14= 8x+4131-14= 8x+4117
(12x+1)-(X+6)= 12x+1-6= 11x-5
(8 at 5)-(40+5)= (40at)-45= 40at-45
3 (12x+5)-(3x+4)= 36x+6-3x-4= 33x+2
(6 7-9) -(44-5)= 58-39= 19
(6x2 +9)- 2x2 4 12) = (12x+9)-(4822x)= 12x+9-4822x= -4810x+9
