find the base k of the number system , if ( 524 ) 8 = ( 664 ) k ?
5 * 8 ^ 2 + 2 * 8 ^ 1 + 4 * 8 ^ 0 = 6 * k ^ 2 + 6 * k ^ 1 + 4 * k ^ 0 320 + 16 + 4 = 6 ( k ^ 2 ) + 6 k + 4 340 = 6 ( k ^ 2 ) + 6 k + 4 6 ( k ^ 2 ) + 6 k + 4 - 340 = 0 6 ( k ^ 2 ) + 6 k - 336 = 0 dividing by 6 ; ( k ^ 2 ) + k - 56 = 0 solving this quadratic equation we get , k = 7 and k = - 8 thus k = 7 answer : d
divide(subtract(sqrt(subtract(const_1, multiply(const_4, divide(divide(subtract(const_4, add(const_4, add(multiply(const_2, 8), multiply(power(8, const_2), divide(const_10, const_2))))), const_3), const_2)))), const_1), const_2)