a) 12a+25+15a-6=27a+19
b) 14p-6-15p+5=-p-1
c) -10+15m-2m-16=13m-26
d) 6x^2-8x+5x-2x^2=4x^2-3x
e) 6u-12u^2-5u^2-15u=-9u-17u^2
f) -10t^2+5t-6t+10t^2=-t
