a+(a-b)= 2x-(x+4)= 7-(-x+6)= -(x+4)+(x-5)=

a+(a-b)=a+a-b=2a-b 2x-(x+4)=2x-x-4=x-4 7-(-x+6)= 7+x-6=x+1 -(x+4)+(x-5)= -x-4+x-5=-9

a+(a-b)=a+a-b=2a-b 2x-(x+4)=2x-x-4=x-4 7-(-x+6)=7+x-6=x+1 -(x+4)+(x-5)= -x-4+x-5=-9

a+(a-b)= a+a-b= 2a -b 2x-(x+4)=2x -x-4= x-4 7-(-x+6)=7 +x-6=1+x -(x+4)+(x-5)=-x-4 +x-5=-9