Question

Determina termenul necunoscut x stiind ca 7^x+ 7^x+2=2450.

Answer 1

[tex] 7^{x}+7^{x+2} =2450 \\ \\ 7^{x}+7^{x}\cdot 7^{2} =2450 \\ \\ 7^{x}(1+ 7^{2})=2450 \\ \\ 7^{x}=2450:50 \\ \\ 7^{x}=49 \\ \\ 7^{x}= 7^{2} \\ \\ x=2 [/tex]

Answer 2

7^x+ 7^x+2=2 450
dam factor comun pe 7^x
7^x ( 1 + 7^2 ) = 2 450

7 ^x ( 1 + 49) = 2 450

7^x × 50 = 2 450

7^x = 2 450 : 50

7^x = 49

7^x = 7^2

x = 2