a) a²+2ab+b² +a²-2ab+b² = 2a²+2b² = 2(a²+b²)
b) m²+4m+4 - m²+6m-9 = 10m-5 = 5(2m-1)
c) k²-25 +4-4k+k² = 2k²-4k -21
d) 49-c² - 4c²-4c-1 = -5c²-4c+48
e) 3³+3*3²x +3*3x² +x³ -x³-6x²= 27+27x +9x²+x³ -x³ -6x² = 3x²+27x+27 = 3(x²+9x+9)
f) (2y)³ +3*(2y)²*z +3*2y*z² +z³ + z³ - 3*z²*2y+3*z*(2y)² -(2y)³ =
= 3*4y²z+6z²y+2z³-6z²y +3*4y²z =
12y²z +12y²z +2z³ = 24y²z +2z³ = 2z(12y² +z²)
g) c³ - 3*c²*3d + 3*c*(3d)² + (3d)³ - (c² - 4d²) =
c³ - 9c²d + 27d²c + 27d³ - c² + 4d²
