Question

Dau 20 de puncte la cine ma ajuta!( / inseamna radical)
a)(x+2)^2+(3x-5)^2+(3x-1)(3x+1)
b)(4x-1)^2+(6x+3)(3-6x)-(x+4)^2
c)(5x+1)^2-(9x-1)^2+(/2x -1)(1+/2x)

Answer 1

a) (x + 2)^2 + (3x - 5)^2 + (3x - 1)(3x + 1) = x^2 + 4x + 4 + 9x^2 - 30x + 25 + 9x^2 - 1 = 19x^2 - 26x + 28

b) (4x - 1)^2 + (6x + 3)(3 - 6x) - (x + 4)^2 = 16x^2 - 8x + 1 + 9 - 36x^2 - (x^2 + 8x + 16) = -20x^2 - 8x + 10 - x^2 - 8x - 16 = -21x^2 - 16x - 6

c) (5x + 1)^2 - (9x - 1)^2 + (radical 2x - 1)(1 + radical 2x) = 25x^2 + 10x + 1 - (81x^2 - 18x + 1) + (2x^2 - 1) = 25x^2 + 10x + 1 - 81x^2 + 18x - 1 + 2x^2 - 1 = -54x^2 + 28x - 1