color(white)=-4sqrt(7/8)=−4√78
=-4*sqrt(7/8)=−4⋅√78
=-4*sqrt7/sqrt8=−4⋅√7√8
=-4*sqrt7/sqrt(4*2)=−4⋅√7√4⋅2
=-4*sqrt7/(sqrt4*sqrt2)=−4⋅√7√4⋅√2
=-4*sqrt7/(2*sqrt2)=−4⋅√72⋅√2
=-4*sqrt7/(2*sqrt2)color(red)(*sqrt2/sqrt2)=−4⋅√72⋅√2⋅√2√2
=-4*(sqrt7*sqrt2)/(2*sqrt2*sqrt2)=−4⋅√7⋅√22⋅√2⋅√2
=-4*(sqrt7*sqrt2)/(2*(sqrt2)^2)=−4⋅√7⋅√22⋅(√2)2
=-4*(sqrt7*sqrt2)/(2*2)=−4⋅√7⋅√22⋅2
=-4*(sqrt7*sqrt2)/(4)=−4⋅√7⋅√24
=-color(red)cancelcolor(black)4*(sqrt7*sqrt2)/color(red)cancelcolor(black)(4)
=-sqrt7*sqrt2
=-sqrt14
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Hope this helped!
