If (x − 2)^2=49, then x could be ?

2 answers:

8 0

$(x - 2)^2=49\\ \\ x^2-4x +4 -49=0\\ \\x^2-4x -45 = 0\\ \\\Delta = b^{2}-4ac = (-4)^{2}-4*1* (-45)= 16+180=196 \\ \\x_{1}=\frac{-b-\sqrt{\Delta }}{2a} =\frac{4-\sqrt{196}}{2}=\frac{4-14}{2}=\frac{-10}{2}=-5 \\ \\x_{2}=\frac{-b+\sqrt{\Delta }}{2a} =\frac{4+\sqrt{196}}{2}=\frac{4+14}{2}=\frac{18}{2}=9 \\ \\Answer : \ x=-5 \ or \ x= 9$

luda_lava [24]3 years ago

4 0

(x-2)(x-2)
x^2 -2x -2x +4 =49 (-49 from both sides)
X^2-4x-45
(x+5)(x-9)
x=-5, x=9

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