For what values of x is x2 + 2x = 24 true?
-6 and -4, -4 and 6, 4 and -6, 6 and 4
Solution:
The quadratic equation x2 + 2x = 24 can be written in the standard form x2 + 2x - 24 = 0.
Let us factorize the equation 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 = 2 and c is the constant term = -24.
Step 2: Multiply a and c and find the factors that add up to b.
1 × (-24) = -24
⇒ 6 and -4 are the factors that add up to b.
Step 3: Split bx into two terms.
x2 + 6x - 4x - 24 = 0
Step 4: Take out the common factors by grouping.
x(x + 6) - 4(x + 6) = 0
(x - 4)(x + 6) = 0
By putting the factors equal to zero we get two values of x
x - 4 = 0 and x + 6 = 0
x = 4 and x = -6
Thus, the two values that satisfy the equation are 4 and -6.
For what values of x is x² + 2x = 24 true?
Summary:
For the value of x = 4 and -6, the equation x2 + 2x = 24 is true.
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