A = (-a - b + c) - (-a - b - c)
= -a - b + c + a + b + c
= (a - a) + (b - b) + (c + c)
= 0 + 0 + 2c
= 2c
A = (-a - b + c ) - ( -a - b - c )
A = -a -b - c + a + b + c
A = (-a + a ) + (-b + b ) + (c + c)
A= 0 + 0 + 2c
A= 2c
Vay A= 2c
tik nha
A = (-a-b+c)-(-a-b-c)
= -a-b+c+a+b+c
= (-a+a)-(b-b)+(c+c)
= 0-0+c.2
= c.2
A= -a - b +c + a+b+c
A= (-a+a)+(-b+b) +(c+c)
A= 0+0+2c
A= 2c