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3 years ago

Please someone help give the answer for the following, we need to write an expression for the following

Mathematics

1 answer:

erastovalidia [21]3 years ago

7 0

Ed to know demensions

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X^{2} - 8x + 7 = 0<br> Solve by completing the square. Also can you include steps?

iren [92.7K]

Answer:

{1, 7}

Step-by-step explanation:

Start with x^2 - 8x + 7 = 0.

We want to modify the first two terms to resemble x^2 - ax + b - b, where a is the coefficient (here -8) of the x term and b is the square of half of a.

Here, a = -8. Half of that is -4. The square of -4 is 16, and this is the value of b.

Write out x^2 - 8x as x^2 - 8x + 16 - 16. This is the perfect square of -4, added to x^2 - 8x and then subtracted from the result

Then the original equation, x^2 - 8x + 7 = 0, can be rewritten as:

x^2 - 8x + 16 - 16 + 7 = 0, and then as (x - 4)^2 - 9, or (x - 4)^2 = 9.

We want to solve this result for x. To do this, take the square root of both sides:

x - 4 = ±√9, or x - 4 = ±3.

Adding 4 to both sides, we get:

x = 4 ± 3. Thus, the solutions are x = 4 + 3 = 7 and x = 4 - 3 = 1.

6 0

3 years ago

Read 2 more answers

2x+4y=1<br> 3x-5y=7 <br> solve the simultaneous equations

WITCHER [35]

Answer:

y= -1/2

x=3/2

Step-by-step explanation:

first isolate x

2x+4y=1

2x=1-4y

x=(1-4y)/2

subsitute it in the second equation

look at the pic

4 0

3 years ago

Eric jogged for 47 minutes, ending at 3:35 p.m. When did Eric start his jog?

Mila [183]

Answer:

im pretty sure its c

Step-by-step explanation:

4 0

2 years ago

Find the value of the following 1.8456×101

Alex Ar [27]

Answer:

186.4056

Step-by-step explanation:

Used a calculator, this is correct

4 0

2 years ago

Read 2 more answers

Solve x2 = 12x – 15 by completing the square. Which is the solution set of the equation? Solve x2 = 12x – 15 by completing the s

Svetlanka [38]

Answer: $6+\sqrt{21}\ \text{and}\ 6-\sqrt{21}$

Step-by-step explanation:

Given

Quadratic equation is

$x^2-12x+15=0$

Solving by completing the square method

$\Rightarrow x^2-2\cdot 6\cdot x+15=0\\\text{add and subtract 36}\\\Rightarrow x^2-2\cdot 6\cdot x+15+36-36=0\\\Rightarrow x^2-2\cdot 6\cdot x+36+(-36+15)=0\\\text{using}\ (a-b)^2=a^2+b^2-2ab\\\Rightarrow (x-6)^2-21=0\\\Rightarrow (x-6)^2=21\\\Rightarrow x-6=\pm \sqrt{21}\\\Rightarrow x=6\pm \sqrt{21}$

The solution set of the equation is $6+\sqrt{21}\ \text{and}\ 6-\sqrt{21}$

6 0

2 years ago

Read 2 more answers