Note:
Solve for x in the following equation.
Problem 4.2c:
Answer:
Solution:
Set the equation equal to zero by subtracting 6x and adding 8 to both sides of the equation.
Method 1:
The equation can be written as
The only way a product can equal zero is for aat least one of the factors to have a value of zero:
Method 2:
Subtract 18 from both sides of the equation .
Add to both sides of the equation:
Factor the left side and simplify the right side :
Take the square root of both sides of the equation :
Subtract from both sides of the equation :
Method 3:
The quadratic formula is
In the equation , a is the coefficient of the term, b is the coefficient of the x term, and c is the constant. Simply insert 1 for a, 11 for b, and 18 for c in the quadratic formula and simplify.
Method 4:
Graph
The answers are x=-2 and -9. These answers may or may not be solutions to the original equation. You must check the answers with the original equation.
Check these answers in the original equation.
Check the solution x=-2 by substituting -2 in the original equation for
x. If the left side of the equation equals the right side of the equation
after the substitution, you have found the correct answer.
Since the left side of the original equation is equal to the right side of
the original equation after we substitute the value -2 for x, then
x = -2
is a solution.
Check the solution x = -9 by substituting -9 in the original equation for x. If the left side of the equation equals the right side of the equation after the substitution, you have found the correct answer.
Since the left side of the original equation is equal to the right side of the original equation after we substitute the value -9 for x, then x=-9 is a solution.
The solutions to the equation
are -2 and
If you would like to review the solution to 4.2d, click on Solution.
If you would like to go back to the problem page, click on Problem.
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Author:Nancy Marcus