Question

3 ori 5 la puterea x - 1981 + 4 ori 5 la puterea x - 1983 + 2 ori 5 la puterea x - 1984 = 1985

Answer 1

$3*5^x-1981+4*5^x-1983+2 * 5^x-1984=1985 \\\\ 5^x(3+4+2)-1981(1+2+3)=1985 \\\\ 5^x*9=1985+1981*5 \\\\ 5^x*9=1981(4+5) \\\\ 5^x*9=1981*9 \\\\ 5^x=1981 \\\\ \hbox{ 1981 nu este un multiplu de 5} \Longrightarrow \boxed{5^x\not = 1981}$

Answer 2

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