Răspuns :
a)15 +2a+1 -a +3= a+19
b)2x²-3x+4 +x²+8x -2 -x²= 3x²-x² +5x +2= 2x²+5x+2
b)2x²-3x+4 +x²+8x -2 -x²= 3x²-x² +5x +2= 2x²+5x+2
15+2a+1-a+3=19+a
(2x²-3x+4)-(-x²-8x+2)-x²=2x²-3x+4+x²+8x-2-x²=2x²+5x+2
(2x²-3x+4)-(-x²-8x+2)-x²=2x²-3x+4+x²+8x-2-x²=2x²+5x+2