if a : b : : 3 : 7 , then what is ( 5 a + 2 b ) : ( a - 2 b ) ?
"a / b = 3 / 7 dividing numerator & denominator of ' ( 5 a + 6 b ) / ( a - 2 b ) ' by b , [ 5 ( a / b ) + 2 ] / [ ( a / b ) - 2 ] = [ 5 * ( 3 / 7 ) + 2 ] / [ ( 3 / 7 ) - 2 ] = - 29 / 11 answer : d"
divide(add(multiply(5, 3), multiply(7, 2)), subtract(3, multiply(2, 7)))