Concept:Recognize that 4x2+9y2+12xy=(2x+3y)2. Substitute to simplify the expression into a quadratic.Explanation:Rewrite the given expression: 4x2+9y2+12xy−5(2x+3y)−14=(2x+3y)2−5(2x+3y)−14.Let u=2x+3y. Then the expression becomes u2−5u−14.Factor the quadratic: u2−5u−14=(u−7)(u+2).Substitute back u=2x+3y: (2x+3y−7)(2x+3y+2).Thus the factors are (2x+3y−7) and (2x+3y+2).