All categories

3 years ago

The sum of 15 and a number is equal to 85. What is the number

Mathematics

1 answer:

mars1129 [50]3 years ago

6 0

Answer:

The sum of 15 and a number is

85 - 15 = 70

You might be interested in

Scarlet built a scale model of a ship, using the scale 3 : 32. The measurements of the model are given in the table. Dimension M

FrozenT [24]

$\dfrac{\text{length of model}}{\text{length of ship}}=\dfrac{3}{32}\\\\\text{substitute}\\\\\dfrac{17}{x}=\dfrac{3}{32}\ \ \ |\text{cross multiply}\\\\3x=17\cdot32\\\\3x=544\ \ \ |:3\\\\x=\dfrac{544}{3}\approx181\ (in)$

7 0

3 years ago

Read 2 more answers

As an elearning project manager you need to plan the development of an 8 module course each module takes 11 hours to update how

andreyandreev [35.5K]

Answer:

number 6

Step-by-step explanation:

6 0

3 years ago

For a food truck event, you sold 750 chicken tacos and 520 beef tacos.

Nesterboy [21]

Answer: 750x+520y=total cost

Step-by-step explanation:

750x+520y=total cost

7 0

3 years ago

Read 2 more answers

Darren has a wooden board that is Three-fifths of a meter long. He cuts the board into 3 equal parts. How long is each section o

Alik [6]

Answer:

Each section of the board is 1/3 or 0.334(0.333333333333) of a meter

Step-by-step explanation:

3/5 divided by 3 is the equation we have to do.

3/5 divided by 3 is also equal to 3/5 times the reciprocal of 3 or 1/3

3/5 * 1/3

3*1 = 3

5*3 = 15

3/15 which can simplify to 1/3. (divide numerator and denominator by 3.)

Each section of the board is 1/3 or 0.334(0.333333333333) of a meter

8 0

2 years ago

If the sum of the zereos of the quadratic polynomial is 3x^2-(3k-2)x-(k-6) is equal to the product of the zereos, then find k?

lys-0071 [83]

Answer:

Step-by-step explanation:

So I'm going to use vieta's formula.

Let u and v the zeros of the given quadratic in ax^2+bx+c form.

By vieta's formula:

1) u+v=-b/a

2) uv=c/a

We are also given not by the formula but by this problem:

3) u+v=uv

If we plug 1) and 2) into 3) we get:

-b/a=c/a

Multiply both sides by a:

-b=c

Here we have:

a=3

b=-(3k-2)

c=-(k-6)

So we are solving

-b=c for k:

3k-2=-(k-6)

Distribute:

3k-2=-k+6

Add k on both sides:

4k-2=6

Add 2 on both side:

4k=8

Divide both sides by 4:

k=2

Let's check:

$3x^2-(3k-2)x-(k-6) \text{ with }k=2$ :

$3x^2-(3\cdot 2-2)x-(2-6)$

$3x^2-4x+4$

I'm going to solve $3x^2-4x+4=0$ for x using the quadratic formula:

$\frac{-b\pm \sqrt{b^2-4ac}}{2a}$

$\frac{4\pm \sqrt{(-4)^2-4(3)(4)}}{2(3)}$

$\frac{4\pm \sqrt{16-16(3)}}{6}$

$\frac{4\pm \sqrt{16}\sqrt{1-(3)}}{6}$

$\frac{4\pm 4\sqrt{-2}}{6}$

$\frac{2\pm 2\sqrt{-2}}{3}$

$\frac{2\pm 2i\sqrt{2}}{3}$

Let's see if uv=u+v holds.

$uv=\frac{2+2i\sqrt{2}}{3} \cdot \frac{2-2i\sqrt{2}}{3}$

Keep in mind you are multiplying conjugates:

$uv=\frac{1}{9}(4-4i^2(2))$

$uv=\frac{1}{9}(4+4(2))$

$uv=\frac{12}{9}=\frac{4}{3}$

Let's see what u+v is now:

$u+v=\frac{2+2i\sqrt{2}}{3}+\frac{2-2i\sqrt{2}}{3}$

$u+v=\frac{2}{3}+\frac{2}{3}=\frac{4}{3}$

We have confirmed uv=u+v for k=2.

4 0

3 years ago