Question

1. (x+7)^3=49(x+7)
2. T=2√l. найдите l при T= 16

Answer 1

$(x+7)^3=49(x+7) t^3=49t t^3-49t=0 t(t^2-49)=0 t=0 t=7 t=-7 x+7=0 x=-7 x+7=7 x=0 x+7=-7 x=-14$

16=2√l

16= √4l

256=4l

l=64   .

Answer 2

1)(х+7)³=49(х+7)

(х+7)³-49(х+7)=0

(х+7)((х+7)²-49)=0

(х+7)(х+7-7)(х+7+7)=0

(х+7)х(х+14)=0

х=-14, -7 или 0

2)T=2√l

√l=T/2

l=T²/4=16²/4=64

Ответ:64