Answer:
Explanation:
STEPS USING FACTORING
a
2
−13a+42=0
To solve the equation, factor a
2
−13a+42 using formula a
2
+(a+b)a+ab=(a+a)(a+b). To find a and b, set up a system to be solved.
a+b=−13
ab=42
Since ab is positive, a and b have the same sign. Since a+b is negative, a and b are both negative. List all such integer pairs that give product 42.
−1,−42
−2,−21
−3,−14
−6,−7
Calculate the sum for each pair.
−1−42=−43
−2−21=−23
−3−14=−17
−6−7=−13
The solution is the pair that gives sum −13.
a=−7
b=−6
Rewrite factored expression (a+a)(a+b) using the obtained values.
(a−7)(a−6)
To find equation solutions, solve a−7=0 and a−6=0.
a=7
a=6