3^( 2x - 1 ) - 3^2x + 3^( 2x + 3 ) = 237 3^2x * ( ( 1/3 ) - 1 + 27 ) = 237 3^2x = 237 : 26 1/3 3^2x = 237 : 79/3 3^2x = 9 3^2x = 3^2 2x = 2 x = 1 -----------------------------5^( 2x - 30 ) - 30*5^( x + 125 ) = 0 5^( 2x - 30 ) = 30*5^( x + 125 ) 5 ^ ( 2x - 30 ) : 5 ^ ( x + 125 ) = 30 5 ^ ( 2x - 30 - x - 125 ) = 30 5 ^ ( x - 155 ) = 30 x - 155 = log₅ 30 x = ( log ₅ 30 ) + 155 --------------------------------------------------( 1/36 ) ^ - 10√x = 2^5x * 3^ 5x ( 6 ^ - 2 ) ^ - 10√x = 6 ^ 5x 6 ^ 20√x = 6 ^ 5x 20√x = 5x √x = a 20a = 5a^2 20a - 5a^2 = 0 5a( 4 - a ) = 0 5a = 0 ==> a = 0 4 - a = 0 ==> a = 4 √ x = 0 ==> x = 0 √ x = 4 ; x = 16