Identify Coefficients: Identify the coefficients of the quadratic expression.The quadratic expression is u2−11u+18. In the standard form of a quadratic expression ax2+bx+c, the coefficient a is the coefficient of u2, b is the coefficient of u, and c is the constant term. For our expression, a=1, b=−11, and c=18.
Find Multiplying Numbers: Find two numbers that multiply to c(18) and add up to b(−11). We need to find two numbers that multiply together to give us 18 and when added together give us −11. The numbers that satisfy these conditions are −9 and −2 because −9×−2=18 and −9+−2=−11.
Write Factored Form: Write the factored form using the two numbers found in the previous step.The factored form of the quadratic expression is (u−9)(u−2), because these factors will multiply to give the original quadratic expression u2−11u+18.