Question

rozwiaz rownanie:

prosze o bardzo dokladne obliczenia+wyjasnienie

Answer 1

Mamy

a1 = 6 x

a2 = 18 x

a3 = 54 x , ... , a10 = 2*3^10 * x

q = 18 x / 6x = 3

zatem  suma

S10 = 6x + 18 x + 54 x + ... + 2*3^10 *x

czyli

S10 = 6x *[ 1 - 3^10]/[ 1 - 3] = 6x *[ 1 - 59 049]/ ( - 2) = - 3x *( - 59 048 )

S10 = 177 144 x

zatem

( 177 144 x)/ (2x + 1) = 265 716

177 144 x = 265 716 *( 2x + 1)

177 144 x = 531 432 x + 265 716

354 288 x = - 265 716

x =  - 265 716 / 354 288 = - 0,75

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