Question

Cu explicație va rog!
$(3x - 1) {}^{2} - 25$
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Answer 1

Folosim a² - b² = (a - b)(a + b)

(3x - 1)² - 25 = (3x - 1 - 5)(3x - 1 + 5) = (3x - 6)(3x + 4)

Answer 2

(3x-1)^2-25=0

Ridicam la pătrat avem:

9x^2-6x+1-25=0

Reducem termenii asemenea:

9x^2+6x-24=o

Aflăm delta:a=9;b=6;c=-24

∆=b^2-4ac=6^2-4•9•(-24)=36+864=900

X1=-b-√∆/2a=-6-30/18=-36/18=-2

X2=-b+√∆/2a=-6+30/18=24/18=4/3

Răspuns:X1=-2

X2=4/3