(a+b)*(a-b) a - b1)= ----------------------------- = -------------------- (a+b)*(a-b) - 8*(a+b) a - b - 8 x² - y² -4x + 4y (x+y)*(x-y) - 4*(x-y) x + y - 42)= --------------------- = ----------------------------- = --------------- (x+y)*(x-y) (x+y)*(x-y) x + y (b - 1)² - c² (b - 1 + c)*(b - 1 - c) b - c - 13) = ------------------------------- = ---------------------------- = ---------------- (b + c)*(b - c) - (b - c) (b - c)*(b + c -1) b - c 10² - (x² - 2xy +y²) 10² - (x - y)²4) = -------------------------------- = -------------------------- = 10*(x + y)+ (x+y)*(x-y) (x+y) * (10 + x -y) (10 + x - y)*(10 - x + y) 10 - x + y= ------------------------------- = --------------------- (10 + x - y)*(x+y) x+ y a² - c² - b*(a + c) (a + c)*(a - c) - b*(a + c)5)= ------------------------ = ---------------------------------- = b² - (a² - 2ac +c²) b² - (a - c)² (a + c)*(a - c - b) (a + c)*(a - b - c) c + a= ----------------------------- = ---------------------------------- = ---------------- (b + a - c)*(b - a + c) (b + a - c)*(-1)*(a - b - c) c - a - b 5² - (a² + 2ab +b²) 5² - (a + b)² (5 +a +b)*(5 -a -b)6) = ------------------------- = -------------------------------- = -------------------------- = a² - 5² + ab + 5b (a + 5)*(a - 5)+b*(a + 5) (a+5)*(a-5+b) (a + b + 5)*(-1)*(a + b - 5) - a - b - 5 a + b+ 5= ----------------------------------- = ------------------ = - ---------------- (a +5) * (a + b - 5) a + 5 a+ 5