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3 years ago

What number must be added to the expression below to complete the square x^2+8x-5=15

Mathematics

1 answer:

Rasek [7]3 years ago

5 0

Answer:

Add 16 to both sides.

General Formulas and Concepts:

Pre-Alg

Equality Properties

Algebra I

Completing the Square: b/2a

Step-by-step explanation:

Step 1: Define expression

x² + 8x - 5 = 15

Step 2: Solve

Isolate x terms: x² + 8x = 20
Complete the Square: (x² + 8x + 16) = 20 + 16
Simplify: (x + 4)² = 36

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1/3+1/3x+8/3=-1/3(6x+11)

ivann1987 [24]

Answer:

x=-20/7 or -2.857

Step-by-step explanation:

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3 years ago

Mary and Jane have rectangular pools that are similar in shape. Mary’s pool dimensions are 2.1 times the corresponding dimension

Naddik [55]

Answer:

Step-by-step explanation:

Let's assume the first pool to have dimensions 3.0 by 2.0

The second pool being 2.1 times the first will have dimensions 6.3 * 4.2

The area of the first pool is 6.0 and that of the second is 26.46

making the area of the second pool 4.41 times that of the first.

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4 years ago

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Luda [366]

Answer:

The approximant serface area should be 11 Inches.

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Step-by-step explanation:

6 0

3 years ago

Rudik [331]

Answer:

The ratio of their volumes is: $\frac{729}{64}$

Step-by-step explanation:

If the cones are similar, then the ratio of their heights should equal the ratio of their radiuses. If we call R the radius of the larger cone (the one of height 9 cm) and r the radius of the smaller cone (the one of height 4 cm), then the following proportion should be verified:

$\frac{R}{r} =\frac{9}{4} \\R=\frac{9\,r}{4}$

where we have solved for "R" in terms of "r".

Now we input this information in the formula for the volume (V) of the largest cone, and for the volume (v) of the smaller cone, recalling that the volume of a cone is the product of the area of the cone's circular base ( $\pi *\,radius^2$ ).

$v=\frac{\pi\,r^2\,4\,}{3} =\pi r^2\,\frac{4}{3} \\V=\frac{\pi\,R^2\,9}{3}=\frac{\pi\,(\frac{9\,r}{4} )^2\,9}{3}=\frac{\pi\,r^2\,729}{16*3}=\pi r^2\,\frac{243}{16}$