Question

Va rog frumos rezolvați exercițiile din imagine

Answer 1

1.a) rad(4*2) + rad(2*25) = 2rad2 + 5rad2 = 7rad2
b) (rad3 +1)(rad3-1) = 3 - 1 = 2
c) (rad5 + rad2)^2 = 5+2rad10 +2 = 7+rad10
2.a) 2x = 2011-2011 =0 => x = 0
b) x^2 = 25 => x = rad25 => x = +/-5
c) |x-9| = 8 => x-9 =8 => x1 = 17
         -(x-9) =8 => -x = -1 => x2 = 1
3).a) x^2+8x+16 = (x + 4)^2 = (x+4)(x+4)
b) x^2-49 = (x-7)(x+7
c) x^2 +x-6 = x^2 -2x +3x-6 = x(x-2) +3(x-2) =(x-2)(x+3)
d) (4x-3)^2-(3x-2)^2 =(4x-3-3x+2)(4x-3+3x-2)=(x-1)(7x-5)
e) x^2-1/4 = (x-1/2)(x+1/2)
f) x^2-2x-15 = x^2-5x+3x-15= x(x-5)+3(x-5)=(x-5)(x+3)