(2x - 3)² = 169
(2x)² - 2 · 2x · 3 + 3² = 169
4x² - 12x + 9 = 169 /-169
4x² - 12x - 160 = 0
a = 4
b = -12
c = -160
Δ = b² - 4ac
Δ = (-12)² - 4 · 4 · (-160)
Δ = 144 + 2560
Δ = 2704
x₁ = [tex] \frac{-b+ \sqrt{delta} }{2a}= \frac{-(-12)+ \sqrt{2704} }{2*4} = \frac{64}{8}=8 [/tex]
x₂ = [tex] \frac{-b- \sqrt{delta} }{2a} = \frac{-(-12)- \sqrt{2704} }{2*4}= \frac{12-52}{8}=-5 [/tex]
/robertinni
