Combine Like Terms: Combine like terms in the expression 2x2−6x+3−8x2−12x+5. We need to add or subtract the coefficients of the terms with the same variable and exponent. 2x2−8x2=−6x2−6x−12x=−18x3+5=8 So, the combined expression is −6x2−18x+8.
Factor Out GCF: Factor out the greatest common factor (GCF) from the expression −6x2−18x+8.The GCF of −6x2, −18x, and 8 is −2.So, we factor out −2 from each term.−6x2/−2=3x2−18x/−2=9x8/−2=−4The factored expression is −2(3x2+9x−4).
Factor Quadratic Expression: Factor the quadratic expression 3x2+9x−4. We look for two numbers that multiply to (3)(−4)=−12 and add to 9. The numbers 12 and −1 work because 12×−1=−12 and 12+(−1)=11, which is not 9. This is a mistake.