Q.4) Factorise :
x2 - 13x + 42
Answers
Answer:
value of x is 6 or 7..........
Answer:
Simplifying
x2 + 13x + 42 = 0
Reorder the terms:
42 + 13x + x2 = 0
Solving
42 + 13x + x2 = 0
Solving for variable 'x'.
Factor a trinomial.
(7 + x)(6 + x) = 0
Subproblem 1
Set the factor '(7 + x)' equal to zero and attempt to solve:
Simplifying
7 + x = 0
Solving
7 + x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-7' to each side of the equation.
7 + -7 + x = 0 + -7
Combine like terms: 7 + -7 = 0
0 + x = 0 + -7
x = 0 + -7
Combine like terms: 0 + -7 = -7
x = -7
Simplifying
x = -7
Subproblem 2
Set the factor '(6 + x)' equal to zero and attempt to solve:
Simplifying
6 + x = 0
Solving
6 + x = 0
Move all terms containing x to the left, all other terms to the right.
Add '-6' to each side of the equation.
6 + -6 + x = 0 + -6
Combine like terms: 6 + -6 = 0
0 + x = 0 + -6
x = 0 + -6
Combine like terms: 0 + -6 = -6
x = -6
Simplifying
x = -6
Solution
x = {-7, -6}