Identify Coefficients: Identify the coefficients a, b, and c in the quadratic expression x2+9x+20. The quadratic expression is in the form ax2+bx+c, where a=1, b=9, and c=20.
Find Multiplying Numbers: Find two numbers that multiply to c (which is 20) and add up to b (which is 9).The two numbers that satisfy these conditions are 4 and 5, because 4×5=20 and 4+5=9.
Write Factored Form: Write the factored form of the quadratic expression using the two numbers found in the previous step.The factored form is (x+4)(x+5), because when expanded, (x+4)(x+5) gives x2+4x+5x+20, which simplifies to x2+9x+20.
More problems from Factor quadratics with leading coefficient 1