Mathematics · Grades 9–11
Roots from factors
Set each factor equal to zero and check the original equation.
The key idea
Set each factor equal to zero and check the original equation.
uv = 0 → u = 0 or v = 0
Worked examples
Find the smaller root of (x − 24)(x − 26) = 0.
x = 24 or x = 26; 24 < 26
24
Find the smaller root of (x − 19)(x − 31) = 0.
x = 19 or x = 31; 19 < 31
19
Try it yourself
Find the smaller root of (x − 4)(x − 9) = 0.
Find the smaller root of (x − 5)(x − 6) = 0.
Check your understanding
Answers and marking notes
- 4
x = 4 or x = 9; 4 < 9
- 5
x = 5 or x = 6; 5 < 6
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Learning preview · teacher review required. Grade bands are approximate, not official curriculum alignment.