For what value of k, -4 is a zero of polynomial x2-x-(2k+2)?
1 answer:
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The equation (form) is:
The solution of the equation is:
Explanation:
First, let's call the number we are going to solve for "x".
Then two thirds of this number can be written as:
Then "plus 4" means add 4 we get:
"is 7" means that the above expression is equal to 7 (as follows):
The solution of the above equation is:
Answer:
x ≈ 1.32, x ≈ - 5.32
Step-by-step explanation:
Given
x² + 4x - 7 = 0 ( add 7 to both sides )
x² + 4x = 7
To complete the square
add ( half the coefficient of the x- term )² to both sides
x² + 2(2)x + 4 = 7 + 4
(x + 2)² = 11 ( take the square root of both sides )
x + 2 = ± ( subtract 2 from both sides )
x = - 2 ±
Thus
x = - 2 - ≈ - 5.32 ( to 2 dec. places )
x = - 2 + ≈ 1.32 ( to 2 dec. places )