Question

Rezolvati in R ecuatia:
a) (x-3)(x+4)-2(3x-2)=(x-4)²
b) (x+5)(x+2)-3(4x-3)=(x-5)²
c) x(x+2)-13=(x-3)(x+3)
d)4x(x-1)=(2x+5)(2x-5)+1

Answer 1

A) (x-3)(x+4)-2(3x-2)=(x-4)^2
X^2 +x -12 -6x +4 = x^2 -8x +16
-5x -8 = -8x +16 /+8x+8
3x = 24 /÷3
X = 8
B) (x+5)(x+2)-3(4x-3) = (x-5)^2
X^2 +7x +10 -12x +9 = x^2 -10x +25
-5x+19 = -10x +25 /+10x-19
5x = 6
X = 1,2
C) x(x+2)-13 = (x-3)(x+3)
X^2 +2x -13 = x^2 -9 /-x^2
2x-13 = -9 /+13
2x = 4 /÷2
X=2
D) 4x(x-1)=(2x+5)(2x-5)+1
4•x^2 -4x = 4•x^2 -25 +1 /-4•x^2
-4x = -24 /÷(-4)
X = 6