Math, asked by kinshuk2406, 11 months ago

Simplify
x^2-3x-1
PLEASE ANSWER FAST.......

Answers

Answered by BrainlyConqueror0901
6

\blue{\bold{\underline{\underline{Answer:}}}}

\green{\tt{\therefore{x =  \frac{3 \pm \sqrt{13} }{2}}}}\\

\orange{\bold{\underline{\underline{Step-by-step\:explanation:}}}}

 \green{\underline \bold{Given: }} \\  \tt:  \implies  {x}^{2} - 3x - 1 = 0 \\  \\ \red{\underline \bold{To \: Find: }} \\  \tt:   \implies value \: of \: x = ?

• According to given question :

\tt:  \implies  {x}^{2}  - 3x - 1 = 0 \\  \\  \tt \circ \: a = 1 \\  \\  \tt \circ \: b =  - 3 \\  \\  \tt \circ \: c =  - 1\\  \\  \bold{As \: we \: know \: that} \\  \tt:  \implies D=  {b}^{2}  - 4ac \\  \\ \tt:  \implies  D =  {( - 3)}^{2}  - 4 \times  1 \times ( - 1) \\  \\ \tt:  \implies  D = 9 + 4 \\  \\ \tt:  \implies  D= 13 \\  \\  \tt:  \implies  x =  \frac{ - b \pm \sqrt{D} }{2a}  \\  \\ \tt:  \implies  x =  \frac{ - ( - 3) \pm \sqrt{13} }{2 \times 1}  \\  \\  \green{\tt:  \implies x =  \frac{3 \pm \sqrt{13} }{2} }

 \bold{Alternate \: method} \\  \tt:  \implies {x}^{2}  - 3x - 1 = 0 \\  \\  \tt Both \: side \: adding \:  (\frac{b}{2a})^{2} =  (\frac{ - 3}{2 \times 1} )^{2}  =  \frac{9}{4}  \\  \\ \tt:  \implies  {x}^{2}  - 3x +  \frac{9}{4}  - 1 =  \frac{9}{4}  \\  \\ \tt:  \implies   {(x -  \frac{3}{2}) }^{2}  =  \frac{9}{4}  + 1 \\  \\ \tt:  \implies   {(x -  \frac{3}{2} )}^{2}  =  \frac{9 + 4}{4}  \\  \\ \tt:  \implies  x -  \frac{3}{2} =  \sqrt{ \frac{13}{4} }  \\  \\ \tt:  \implies x -  \frac{3}{2}  =  \pm \frac{13}{2}  \\  \\  \green{\tt:  \implies  x =  \frac{3 \pm \sqrt{13} }{2} }

Answered by phunguyen22111901
2

Answer:(x-\frac{3+\sqrt{13} }{2}).(x-\frac{3-\sqrt{13} }{2})

Step-by-step explanation:

first, you need to find Δ= b^{2}-4ac = 13

then get x1,x2=\frac{3+\sqrt{13} }{2}, \frac{3-\sqrt{13} }{2}

second, the simplify will be (x-\frac{3+\sqrt{13} }{2}).(x-\frac{3-\sqrt{13} }{2})

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