Solve for x

ign="absmiddle" class="latex-formula">

Mathematics

1 answer:

Makovka662 [10]3 years ago

8 0

Answer:

x = -7

Step-by-step explanation:

Subtract 15 from both sides of the equation.

x = 8 -15 = -7

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Suppose a and b are the solutions to the quadratic equation 2x^2-3x-6=0. Find the value of (a+2)(b+2).

KonstantinChe [14]

Answer:

(a+2)(b+2) = 4

Step-by-step explanation:

We are given the following quadratic equation:

$2x^2-3x-6=0$

Let a a and b be the solution of the given quadratic equation.

Solving the equation:

$2x^2-3x-6=0\\\text{Using the quadratic formula}\\\\x = \dfrac{-b \pm \sqrt{b^2-4ac}}{2a}\\\\\text{Comparing the equation to }ax^2 + bx + c = 0\\\text{We have}\\a = 2\\b = -3\\c = -6\\x = \dfrac{3\pm \sqrt{9-4(2)(-6)}}{4} = \dfrac{3\pm \sqrt{57}}{4}\\\\a = \dfrac{3+\sqrt{57}}{4}, b = \dfrac{3-\sqrt{57}}{4}$

We have to find the value of (a+2)(b+2).

Putting the values:

$(a+2)(b+2)\\\\=\bigg(\dfrac{3+\sqrt{57}}{4}+2\bigg)\bigg(\dfrac{3-\sqrt{57}}{4}+2\bigg)\\\\=\bigg(\dfrac{11+\sqrt{57}}{4}\bigg)\bigg(\dfrac{11-\sqrt{57}}{4}\bigg)\\\\=\dfrac{121-57}{156} = \dfrac{64}{16} = 4$

3 0

2 years ago

On Monday, Jayla raised $30 and Carlos raised $50.

gayaneshka [121]

Answer:

84 days

Step-by-step explanation:

You would use the LCM to solve this.

12 and 7 don't share any common factors other than 1,

so you would multiply 12 x 7, which gets you 84.

After 84 days they would have raised the same amount.

8 0

3 years ago

A rectangle length is 8cm more than three times it’s widith. The perimeter is 128 cm find the length.

Masteriza [31]

Let x = width
<span>length is 8 cm more than three times it’s width so length = 3x + 8
</span>
Perimeter of a rectangle = 2(L + W)
so
128 = 2(x + 3x + 8) solve for x (width)
128 = 2(4x + 8)
64 = 4x + 8
4x = 56
x = 14
width = 14 cm
length = 3(14) + 8 = 50 cm

Answer:
width = 14 cm
length = 50 cm

4 0

2 years ago

Find the coordinates of the vertex of the following parabola algebraically. Write your answer as an (x,y)(x,y) point.

Serga [27]

Answer:

(8,-3)

Step-by-step explanation:

The given parabola is

$y = - 3 {x}^{2} + 48x - 195$