0
What is the root of the equation m squared -6m -7 equals 0 found by completing the square?
Wiki User
∙ 8y ago
To complete the square for a quadratic ax² + bx + c = 0
1) Divide through by the coefficient of the x² term to get x² + b/a x + c/a = 0; let B = b/a; let C = c/a; the equation is now x² + Bx + c = 0
2) Complete the square by taking half of B and adding it to x and squaring: (x + B/2)²
3) Expanding this gives: (x + B/2)² = x² + Bx + (B/2)² → x² + Bx = (x + B/2)² - (B/2)²
4) Substitute this in the original equation to give: x² + BX + C = (x + B/2)² - (B/2)² + C
5) This can now be solved as (x + B/2)² - (B/2)² + C = 0 → (x + B/2)² = (B/2)² - C
For m² - 6m - 7 = 0, completing the square gives:
(m - 6/2)² - (6/2)² - 7 = 0
→ (m - 3)² - 9 - 7 = 0
→ (m - 3)² -16 = 0
→ (m - 3)² = 16
→ m - 3 = ±4
→ m = 3 ± 4
→ m = 7 or -1.
Wiki User
∙ 8y ago
Wiki User
∙ 8y agoThe coefficient of m is -6 so you need to use -6/2 = -3 for completing the squares.
m^2 - 6m - 70
=> m^2 - 6m = 70
=> (m - 3)^2 = 70 + (-3)^2 = 70 + 9
=> (m - 3)^2 = 79
=> m - 3 = +/- sqrt(79)
=> m = 3 +/- sqrt(79)
Wiki User
∙ 8y agoI think you want: m² - 6m - 70 = 0. Complete the square, so if you have something like
(x - A)², then you will get x² - 2Ax + A². So let's look at it. The coefficient of x is -6, so if -6x equates to -2Ax, then A must be 3.
So we have (m - 3)² = m² - 6m + 9, except you have m² - 6m - 70, so to get it like that we can do this: m² - 6m + 9 - 79 will equal your expression (9 - 79 = -70).
m² - 6m + 9 - 79 = 0. Add 79 to both sides. m² - 6m + 9 = 79
Now remember that m² - 6m + 9 = (m - 3)², so we have (m - 3)² = 79.
Square root of both sides: m - 3 = sqrt(79) and also: m - 3 = -sqrt(79).
Add 3 to both sides: m = 3 + sqrt(79) and m = 3 - sqrt(79)
Add your answer:
Earn +20 pts
How do you solve 2x squared plus x plus 2 equals 0 by completing the square?
It cannot be solved because the discriminant of the quadratic equation is less than zero
11 x 2 -34 x 3 equals to 0 by Completing Square From Quadratic Equation?
If you mean: 11x2-34x+3 = 0 then the solutions are x = 1/11 and x = 3 by completing the square or using the quadratic equation formula
What is the centre and radius of a circle when x squared plus y squared -4x -2y -4 equals 0?
Equation: x^2 +y^2 -4x -2y -4 = 0 Completing the squares: (x-2)^2 +(y-1)^2 -4-1-4 = 0 So: (x-2)^2 +(y-1)^2 = 9 Therefore the centre of the circle is at (2, 1) and its radius is 3
What is the third step in solving this equation by completing the square?
Completing the square is one method for solving a quadratic equation. A quadratic equation can also be solved by several methods including factoring, graphing, using the square roots or the quadratic formula. Completing the square will always work when solving quadratic equations and is a good tool to have. Solving a quadratic equation by completing the square is used in a lot of word problems.I want you to follow the related link that explains the concept of completing the square clearly and gives some examples. that video is from brightstorm.
Solve by completing square 2x² - 6x plus 7 equals 0?
This quadratic equation has no solutions because the discriminant is less than zero.
How do you solve 2x squared plus x plus 2 equals 0 by completing the square?
It cannot be solved because the discriminant of the quadratic equation is less than zero
How can you use the 'completing the square' method to solve an equation when the coefficient of x squared is more than 1?
i want to solve few questions of completing square method can u give me some questions on it
How do you graph the equation x squared plus y squared equals 16?
You are describing a circle, with its center at the origin and a radius of 4 (the square root of 16)
11 x 2 -34 x 3 equals to 0 by Completing Square From Quadratic Equation?
If you mean: 11x2-34x+3 = 0 then the solutions are x = 1/11 and x = 3 by completing the square or using the quadratic equation formula
What equation results from completing the square and then factoring?
A quadratic equation
Which is the best way to solve the equation x squared equals n?
If x squared equals n, then x is the square root of n.
What is an equation that can be used in quadratic formula completing the square and factoring?
A quadratic equation.
What is the centre and radius of a circle when x squared plus y squared -4x -2y -4 equals 0?
Equation: x^2 +y^2 -4x -2y -4 = 0 Completing the squares: (x-2)^2 +(y-1)^2 -4-1-4 = 0 So: (x-2)^2 +(y-1)^2 = 9 Therefore the centre of the circle is at (2, 1) and its radius is 3
What is the third step in solving this equation by completing the square?
Completing the square is one method for solving a quadratic equation. A quadratic equation can also be solved by several methods including factoring, graphing, using the square roots or the quadratic formula. Completing the square will always work when solving quadratic equations and is a good tool to have. Solving a quadratic equation by completing the square is used in a lot of word problems.I want you to follow the related link that explains the concept of completing the square clearly and gives some examples. that video is from brightstorm.
What is the fifth step in solving the equation by completing the square 5x2-12x plus 4 equals 0?
x = 2 or x = 2/5
Solve by completing square 2x² - 6x plus 7 equals 0?
This quadratic equation has no solutions because the discriminant is less than zero.
When a squared plus b squared equals c squared what is the square root of the square root of the square root of a squared squared squared plus b squared squared squared?
Since a squared plus b squared equals c squared, that is the same as c equals the square root of a squared plus b squared. This can be taken into squaring and square roots to infinity and still equal c, as long as there is the same number of squaring and square roots in the problem. Since this question asks for a and b squared three times, and also three square roots of a and b both, they equal c. Basically, they cancel each other out.
