Question

1) (5/6)^4x=(36/25)^-13
2)  5^x-9×5^x-3=580

Answer 1

( 5/6 ) ^ 4X = ( 36/25) ^ - 13 
4X = ( - 2 * ( - 13 ))
4X = 26 
X = 6,5 
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5 ^X - 9 * 5 ^ ( X - 3 ) = 580 
5 ^X * ( 1 - 9 * 5 ^(-3)) = 580 
5 ^X * ( 1 - 9/125) = 580 
5 ^X * 116/125 = 580
5^X = 580 : 116/125 
5^X = 625 
5^X = 5^4
X = 4 
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