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3 years ago

Help please!! i don’t understand this one!

Mathematics

1 answer:

12345 [234]3 years ago

5 0

Answer:

C, D

Step-by-step explanation:

This equation can be solved any of several ways. One that doesn't require much thought is using the quadratic formula.

For ax² +bx +c = 0, the solutions are ...

$x=\dfrac{-b\pm\sqrt{b^2-4ac}}{2a}$

In the given equation, a=2, b=11, c=5, so this becomes ...

$x=\dfrac{-11\pm\sqrt{11^2-4\cdot2\cdot5}}{2\cdot2}=\dfrac{-11\pm\sqrt{81}}{4}\\\\x=\dfrac{-11\pm9}{4}=\left\{-\dfrac{20}{4},-\dfrac{2}{4}\right\}=\{-5,-\frac{1}{2}\}$

The solutions are ...

C. x = -5

D. x = -1/2

_____

My personal favorite is using a graphing calculator. The solutions are the x-intercepts of the expression on the left. That is, where its value is zero, as the equation says.

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elena55 [62]

The correct answer is C-6 and two thirds

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3 years ago

Represent each of these relations on {1, 2, 3, 4} with a matrix (with the elements of this set listed in increasing order). a) {

Irina-Kira [14]

Answer:

for a a) {(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)}

$\left[\begin{array}{cccc}0&1&1&1\\0&0&1&1\\0&0&0&1\\0&0&0&0\end{array}\right]$

for b

b) {(1, 1), (1, 4), (2, 2), (3, 3), (4, 1)}

$\left[\begin{array}{cccc}1&0&0&1\\0&1&0&0\\0&0&1&0\\1&0&0&0\end{array}\right]$

for c) {(1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), (4, 1), (4, 2), (4, 3)}

$\left[\begin{array}{cccc}0&1&1&1\\1&0&1&1\\1&1&0&1\\1&1&1&0\end{array}\right]$

for d d) {(2, 4), (3, 1), (3, 2), (3, 4)}

$\left[\begin{array}{cccc}0&0&0&0\\0&0&0&1\\1&1&0&1\\0&0&0&0\end{array}\right]$

Step-by-step explanation:

in matrix, arrays are placed in rows , which represents the horizontal sides from left to right, while arrays in the column are placed vertically from top to bottom. Here, we placed the arrays in a 4x4 matrix

for a a) {(1, 2), (1, 3), (1, 4), (2, 3), (2, 4), (3, 4)}

$\left[\begin{array}{cccc}0&1&1&1\\0&0&1&1\\0&0&0&1\\0&0&0&0\end{array}\right]$

for b

b) {(1, 1), (1, 4), (2, 2), (3, 3), (4, 1)}

$\left[\begin{array}{cccc}1&0&0&1\\0&1&0&0\\0&0&1&0\\1&0&0&0\end{array}\right]$

for c) {(1, 2), (1, 3), (1, 4), (2, 1), (2, 3), (2, 4), (3, 1), (3, 2), (3, 4), (4, 1), (4, 2), (4, 3)}

$\left[\begin{array}{cccc}0&1&1&1\\1&0&1&1\\1&1&0&1\\1&1&1&0\end{array}\right]$

for d d) {(2, 4), (3, 1), (3, 2), (3, 4)}

$\left[\begin{array}{cccc}0&0&0&0\\0&0&0&1\\1&1&0&1\\0&0&0&0\end{array}\right]$

7 0

3 years ago

How do I find the answer to m

ZanzabumX [31]

Those are vertical angles,so they are equal
150=5m
m=150/5
m=30

3 0

3 years ago

What is the formula for:

Masteriza [31]

Answer:

A) (Triangle) So, the area A of a triangle is given by the formula A=12bh where b is the base and h is the height of the triangle. Example: Find the area of the triangle. The area A of a triangle is given by the formula A=12bh where b is the base and h is the height of the triangle.

B) We know that the general equation for a circle is ( x - h )^2 + ( y - k )^2 = r^2, where ( h, k ) is the center and r is the radius.

C)The parallelogram area can be calculated, using its base and height.

Area = ½ × d1 × d2 sin (y)

All Formulas to Calculate Area of a Parallelogram

Using Base and Height A = b × h

Using Trigonometry A = ab sin (x)

Using Diagonals A = ½ × d1 × d2 sin (y)

D)Area of a trapezoid is found with the formula, A=(a+b)/2 x h. Learn how to use the formula to find area of trapezoids.

Hope this helps!

All the love, Ya boi Fraser :)

7 0

3 years ago

What is the sum of the geometric series in which a1 = −5, r = 3, and an = −405?

xxMikexx [17]

$a_1=-5;\ r=3;\ a_n=-405\\\\a_n=a_1r^{n-1}\\\\subtitute\\\\-5\cdot3^{n-1}=-405\ \ \ |divide\ both\ sides\ by\ (-5)\\\\3^{n-1}=81\\\\3^{n-1}=3^4\iff n-1=4\to n=5\\\\S_n=\dfrac{a_1(1-r^n)}{1-r}\\\\S_5=\dfrac{-5(1-3^5)}{1-3}=\dfrac{-5(1-243)}{-2}=\dfrac{5\cdot(-242)}{2}=5\cdot(-121)=-605\\\\\\Answer:\boxed{S_5=-605}$

4 0

3 years ago