All categories

2 years ago

Solve the equation for all values of x by completing the square. x2 + 8.0 + 15 = 0

Mathematics

1 answer:

Aleonysh [2.5K]2 years ago

6 0

Answer:

x= -3

x= -5

Step-by-step explanation:

x^2 + 8x + 15 = 0

find which 2 numbers when multiplied equal 15 and when added equal 8

they are 3 and 5

(x+3)(x+5)

x+3 =0

x+5=0

x= -3

x= -5

You might be interested in

A counter top is 18 feet long and 3 feet wide. What is the area of the counter top in square meters? Use the conversion 1 foot =

podryga [215]

Answer:

Area of the counter top is $5.02\ m^2$ .

Step-by-step explanation:

Given:

Length of the Counter top = 18 feet

Width of the counter top = 3 feet

We need to find the area of the counter top is square meter;

Solution:

Now we need to find the area of the counter top is square meter.

But given data is in feet so we will first convert feet into meters.

1 foot = 0.305 meter.

So 18 feet = Number of meters in 18 feet.

By Using Unitary method we get;

Number of meters in 18 feet = $18\times 0.305 = 5.49\ m$

Length of the Counter top = 5.49 m

Also 3 feet = Number of meters in 3 feet.

Again Using Unitary method we get;

Number of meters in 3 feet = $3\times 0.305 = 0.915\ m$

Width of the counter top = 0.915 m

Now we know that;

Area of the counter top can be calculated by multiplying Length of the counter top with width of the counter top.

framing in equation form we get;

Area of the counter top = $5.49\times 0.915 = 5.0233\ m^2$

Rounding up to 2 decimals we get;

Area of the counter top = $5.02\ m^2$

Hence Area of the counter top is $5.02\ m^2$ .

3 0

3 years ago

Mayra bought $$ grams of rice. Anika bought $$ more than Mayra bought. Select ALL of the equations that represent the relationsh

Sonja [21]

Answer:

Step-by-step explanation:2

4 0

3 years ago

Factor both quadratic expressions. (x 4 + 5x 2 - 36)(2x 2 + 9x - 5) = 0

Sonbull [250]

So focusing on x^4 + 5x^2 - 36, we will be completing the square. Firstly, what two terms have a product of -36x^4 and a sum of 5x^2? That would be 9x^2 and -4x^2. Replace 5x^2 with 9x^2 - 4x^2: $x^4+9x^2-4x^2-36$

Next, factor x^4 + 9x^2 and -4x^2 - 36 separately. Make sure that they have the same quantity inside of the parentheses: $x^2(x^2+9)-4(x^2+9)$

Now you can rewrite this as $(x^2-4)(x^2+9)$ , however this is not completely factored. With (x^2 - 4), we are using the difference of squares, which is $a^2-b^2=(a+b)(a-b)$ . Applying that here, we have $(x+2)(x-2)(x^2+9)$ . x^4 + 5x^2 - 36 is completely factored.

Next, focusing now on 2x^2 + 9x - 5, we will also be completing the square. What two terms have a product of -10x^2 and a sum of 9x? That would be 10x and -x. Replace 9x with 10x - x: $2x^2+10x-x-5$