Salut!
Hai sa ne reamintim!
[tex](a+b)^{2} = a^{2} + 2ab + b^{2} \\(a-b)^{2} = a^{2} - 2ab + b^{2}\\(a+b)(a-b) = a^{2} - b^{2}[/tex]
Asadar,
a) [tex](x+2)^2 + 16 = (x+5)^2\\x^2 + 4x + 2^2 +16 = x^2 + 10x + 5^2\\x^2 + 4x + 20 = x^2 + 10x + 25 /-25 - x^2 - 4x\\6x = -5[/tex]
b) [tex](2x - 1)^2 = 4(x+1)^2 + 5\\4x^2 - 4x + 1 = 4(x^2 + 2x + 1) + 5\\4x^2 - 4x + 1 = 4x^2 + 8x + 4 + 5\\4x^2 - 4x + 1 = 4x^2 + 8x + 9 /-9 -4x^2 + 4x\\12x = -8[/tex]
c) [tex](3x - 1)^2-1-9(x-2)(x+2) = 0\\9x^2 - 6x + 1 - 1 - 9(x^2 - 4) = 0\\9x^2 -6x - 9x^2 + 47 = 0\\-6x = -47 / *(-1)\\6x = 47[/tex]
d) [tex]16(x-3)(x+3) = (4x - 2)^2\\16(x^2-9) = 16x^2 -16x + 4\\16x^2 - 144 = 16x^2 - 16x +4 /-16x^2 - 4\\-144 = -16x / *(-1)\\16x = 144[/tex]
Sper ca te-am ajutat, mult succes! Coroana?
