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katen-ka-za [31]
3 years ago
12

Solve for x 15x^2+16x= -4

Mathematics
2 answers:
Klio2033 [76]3 years ago
4 0
15x²+16x+4 =0      (ax² +bx +c=0)

Δ = b²-4ac =256 - 4×15×4 =16

x1 = (-b+√Δ) / 2a = (-16+√16) / 30 =( -16+4) / 30 = -12/30 = - 2/5
x2 = (-b -√Δ) / 2a = (-16 -√16) / 30 = (-16 -4) /30 = -20/30 = -2/3
Alecsey [184]3 years ago
4 0
      15x² + 16x = -4
15x² + 16x + 4 = -4 + 4
15x² + 16x + 4 = 0
x = <u>-(16) +/- √((16)² - 4(15)(4))</u>
                       2(15)
x = <u>-16 +/- √(256 - 240)</u>
                     30
x = <u>-16 +/- √(16)
</u>              30
x = <u>-16 +/- 4</u>
            30
x = <u>-8 +/- 2</u>
          15
x = <u>-8 + 2</u>  or  x = <u>-8 - 2</u>
         15                  15
x = <u>-6</u>             x = <u>-10</u>
      15                   15
x = ⁻²/₅            x = ⁻²/₃
<u />
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OLga [1]

Answer:

3. Option D

5. Option B

13. Option D

17. Option B

Step-by-step explanation:

<u>Question 3</u>

4C means that, multiply 4 with  all the terms in the matrix A . We get option D.

<u>Question 5</u>

Matrix A + matrix B  means that add corresponding terms of each matrix.

We get option B.

<u>Question 13</u>

Here we have to find a₁,₂ (the term in which first row second column)

a₁,₂ = 2

We get option D.

<u>Question 17</u>

B - CF - First multiply matrix C with matrix F and subtract it from Matrix B.

We get option B

5 0
3 years ago
One of the legs of a right triangle measures 13 cm and the other leg measures 7 cm. Find the measure of the hypotenuse. If neces
garri49 [273]
Answer:14.8

Step-by-step:
Use the equation a^2+b^2=c^2
Plug in 13 for a and 7 for b
13^2+7^2=c^2
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8 0
2 years ago
Help me with this question please.
Vlada [557]

Answer:

The number of Pencils purchased and the cost of pencils represents a proportional relationship.

Step-by-step explanation:

As we know that proportional relationships between two variables have equivalent ratios.

For example,

3/12 = 9/36 is a TRUE proportions because both fractions reduces to 1/4, and because  12 × 9 = 3 × 36.

As our problem suggests whether the number of Pencils purchased and the cost of pencils represent a proportional relationship?

Given

  • Pencils $0.25 each

It means ach pencil costs $0.25.

So

  • If Sarah buys 1 pencil it would cost = $0.25
  • If Sarah buys 2 pencils it would cost = $0.5
  • If Sarah buys 3 pencils it would cost = $0.75
  • If Sarah buys 4 pencils it would cost = $1

Lets make a table:

No of Pencils Purchased               Cost

                  1                                   $0.25

                  2                                   $0.5

                  3                                   $0.75

                  4                                   $1

so

Cost/No of Pencils Purchased = 0.25/1 = 0.5/2 = 0.75/3 = 1/4

So cost per pencil = 0.25 : 1

Since all of the ratios are equivalent, this table is a proportional relationship.

Therefore, the number of Pencils purchased and the cost of pencils represents a proportional relationship.

7 0
3 years ago
3^-1 ___ 1/4<br><br> =<br> &lt;<br> &gt;<br> answer thanks
dybincka [34]

3⁻¹  is <u>greater than </u>1/4

<u>Step-by-step explanation:</u>

3⁻¹ is nothing but the inverse of 3 .

So it can be written as 1/3.

Value of 1/3 can be found by dividing 1 by 3 to be 0.333...

Value of 1/4 can be found by dividing 1 by 4 to be 0.25

So 0.333 > 0.25

1/3 > 1/4

∴ 3⁻¹ > 1/4

6 0
4 years ago
30 POINTS NEED HELP
KatRina [158]

a. The expression y=5x represent the number of small marbles she has.

b. The expression z=3x+2 represents the number of large marbles she has.

c. Amy has 310 small marbles, 62 medium marbles and  188 large marbles.

Step-by-step explanation:

a. Let x represent the number of medium marbles Amy has. Write an algebraic expression to represent the number of small marbles she has.

Medium marbles = x

Let,

Small marbles = y

According to given statement;

She has five times as many small marbles as medium marbles.

y = 5x        Eqn 1

The expression y=5x represent the number of small marbles she has.

b. Write an algebraic expression to represent the number of large marbles she has.

Let,

Large marbles = z

The number of large marbles is two more than three times the number of medium marbles.

z = 3x+2        Eqn 2

The expression z=3x+2 represents the number of large marbles she has.

c. If Amy has a total of 560 marbles, how many of each size does she have?

x+y+z= 560     Eqn 3

Putting value of y and z from Eqn 1 and 2 in Eqn 3

x+(5x)+(3x+2)=560\\x+5x+3x+2=560\\9x=560-2\\9x=558

Dividing both sides by 9

\frac{9x}{9}=\frac{558}{9}\\x=62

Putting x=62 in Eqn 1

y=5(62)\\y=310

Putting x=62 in Eqn 2

z=3(62)+2\\z=186+2\\z=188

Amy has 310 small marbles, 62 medium marbles and  188 large marbles.

Keywords: linear equation, substitution method

Learn more about substitution method at:

  • brainly.com/question/11416224
  • brainly.com/question/11638377

#LearnwithBrainly

5 0
3 years ago
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