Question

Efectuati.
a) 5m+{3n+[6p-2m-(m-p)]} - [9m-(7n+p)];
b) 2x^2 -3x -{-x+(x^2 -2x) - [3x^2-(2x-x^2)-(2x^2-2x)]};
c) 15a^2-{-4a+[5a-8a^2-(2a^2-a)+9a^2]-3a};
d) (3x+5y)-{9x-[6x+2y-(12x-10y)]-x-(7x-4y)};

Answer 1

a) 5m+{3n+[6p-2m-(m-p)]} - [9m-(7n+p)]=
=5m+3n+[6p-2m-m+p)] - 9m+7n+p=
=5m+3n+7p-3m - 9m+7n+p=
=10n+8p-7m


 b) 2x² -3x -{-x+(x² -2x) - [3x²-(2x-x²)-(2x²-2x)]}=
=2x² -3x -{-x+x² -2x - [3x²-2x+x²-2x²+2x)]}=
=2x² -3x -{-3x+x² - 2x²}
=2x² -3x -(-3x- x²)=
=2x² -3x +3x + x²)=
=2x² -3x +3x + x²=
=3x²


 c) 15a²-{-4a+[5a-8a²-(2a²-a)+9a²]-3a}
=15a²-{-4a+[6a-a²]-3a}=
=15a²-{-4a+6a-a²-3a}=
=15a²-{-a-a²}=
=15a²+a+a²
=16a²+a

 d) (3x+5y)-{9x-[6x+2y-(12x-10y)]-x-(7x-4y)}=
=(3x+5y)-[9x-(6x+2y-12x+10y)-x-7x+4y]=
=(3x+5y)-[9x-(-6x+12y)-8x+4y]=   
=(3x+5y)-[9x+6x-12y-8x+4y]=   
=(3x+5y)-(7x-8y)=   
=3x+5y-7x+8y=   
=-4x+13y