a) F=x, G= -6x + 4
F+G = x+(-6x)+4= -5x +4
F-G = x - (-6x+4) = 7x - 4
b) F=8, G= -(4x + 5)
F+G = 8 - 4x - 5= 3-4x
F-G = 8+4x+5 = 13+4x
c) F=a do kwadratu, G= 8 - a do kwadratu
F+G = a^2 + 8 - a^2 = 8
F-G = a^2 - 8 + a^2 = 2a^2 - 8
d) F = 2x - y, G= -(x - 2y)
F+G = 2x - y + 2y - x = x+y
F-G = 2x - y +x-2y = 3x - 3y
e) F = -(2a-b), G= 2a + b
F+G = -2a+b + 2a +b = 2b
F-G = -2a +b -2a - b = -4a
f) F = -(a-b), G= -(a + b)
F+G = -a +b -a -b = -2a
F-G = -a +b +a+b = 2b