Question

Simplificar expressoes :  ?! calculo pfv :)
 a) (2a-3)² - 4(a-1)(a+1) + 5
b)(5y+2)² - (5y-2)² - (5y+2)(5y-2)
c) (x+y)² - (x²+y²)

Answer 1

a) (2a-3)² - 4(a-1)(a+1) + 5 
    4a²+12a+9-4(a²-1)+5
    4a²+12a+9-4a²+4+5
    4a²-4a²+12a+4+5
    12a+9

b)(5y+2)² - (5y-2)² - (5y+2)(5y-2)
   25y²+20y+4 - (25y²-20y+4) - 25y²-4
   25y²+20y+4-25y²+20y-4-25y²-4
   25y²-25y²-25y²+20y+20y+4-4-4
   -25y²+40y-4

c) (x+y)² - (x²+y²)
    x²+2xy+y²-x²-y²
    x²-x²+2xy+y²-y²
    2xy