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What are the zeroes of f(x) = x2 + 5x + 6?
x = -2, -3
x = 2, 3
x = -2, 3
x = 2, -3
Solution:
The zeroes of the polynomial make the values of the whole polynomial equal to zero.
Let us factorise the polynomial to find the value of x by splitting the middle term.
Step 1:
Identify the values of a, b and c.
In the above equation, a is coefficient of x2 = 1,
b is the coefficient of x which is 5 and c is the constant term = 6.
Step 2:
Multiply a and c and find the factors that add up to b.
1 × (6) = 6
⇒ 3 and 2 are the factors that add up to b.
Step 3:
Split 5x into two terms.
x2 + 3x + 2x + 6 = 0
Step 4:
Take out the common factors by grouping.
x(x + 3) + 2 (x + 3) = 0
(x + 3) (x + 2) = 0
By putting the factors equal to zero we get two values of x
x + 3 = 0 and x + 2 = 0
x = - 3 and x = - 2
Thus, the two values that satisfy the equation are - 3 and - 2.
What are the zeroes of f(x) = x2 + 5x + 6?
x = -2, -3, x = 2, 3, x = -2, 3 x = 2, -3
Summary:
The zeroes of f(x) = x2 + 5x + 6 are x = -3, -2 which satisfies the equation.
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