Mathematics: Hi, anyone able to help with qn 7? Thanks :)!

Hi, anyone able to help with qn 7? Thanks :)! - id79316555, delaneynagle3368

lolweapon

10.02.2022

Step-by-step explanation:

I used the quadratic formula to find the roots of $x^{2} + x -1$

$a=\frac{-1-\sqrt{5}}{2} b=\frac{-1+\sqrt{5} }{2}$

$\frac{1 }{\sqrt{3} } *(\frac{-1-\sqrt{5}}{2} )^{2} * \frac{-1+\sqrt{5}}{2}$

$\frac{1 }{\sqrt{3} } *(\frac{-1-\sqrt{5}}{2} ) * \frac{-1+\sqrt{5}}{2}*(\frac{-1-\sqrt{5}}{2} )$

$\frac{1 }{\sqrt{3} } *(\frac{-1-\sqrt{5}}{2} ) * \frac{-1+\sqrt{5}-\sqrt{5} -4}{4}$

$\frac{1 }{\sqrt{3} } *(\frac{-1-\sqrt{5}}{2} ) * \frac{ -4}{4}$

$\frac{1 }{\sqrt{3} } *(\frac{-1-\sqrt{5}}{2} ) * -1$

$\frac{-1-1\sqrt{5} }{2\sqrt{3} }*-1$

$\frac{-1-1\sqrt{5} }{2\sqrt{3} } = \frac{\sqrt{5}+1 }{2\sqrt{3} }$

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zemathes

01.01.2020

they sell 240 sw =)))

Step-by-step explanation:

x= the number of b water they sold

y= the number of sw they sold

because they sold a total of 390 items => x+y= 390 (1)

because they sold water for $2 a bottle and the sandwiches for $4 each => 2x + 4y= 1260 (2)

(1) and (2) => x=150 ; y=240.

i hope this will help you =)))

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