All categories

3 years ago

Dexter had 15 fish in his fish tank. 7 were

Mathematics

1 answer:

melamori03 [73]3 years ago

6 0

Answer:12

Step-by-step explanation: so sart by subtracting 15 and 7

15-7

this gives you 8

now add 4

8+4

this gives you 12

You might be interested in

2x^2=9-3x <br> Find the factors

d1i1m1o1n [39]

Answer:

x = -3, $\frac{3}{2}$

Step-by-step explanation:

The given quadratic equation is: $2x^2 = 9 - 3x$

This can be written as: $2x^2 + 3x - 9 = 0$

To solve a quadratic equation of the form $ax^2 + bx + c = 0$ we use the formula:

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

Here, a = 2; b = 3; c = - 9

Therefore, the roots of the equation are:

$x = \frac{- 3 \pm \sqrt{9 - 4(2)(-9)}}{2(2)}$

$\implies x = \frac{-3 \pm \sqrt{81}}{4}$

$\implies x = \frac{-3 \pm 9}{4}$

We get two values of 'x', viz.,

x = $\frac{-3 + 9}{4}$ and $\frac{- 3 - 9}{4}$

$\implies x = \frac{6}{4} \hspace{5mm} \& \hspace{5mm} \frac{-12}{4}$

⇒ x = -3, 3/2

Since the factors of the quadratic equation is asked, we write it as:

(x + 3)(x - $\frac{3}{2}$ ) = 0

because, if (x - a)(x - b) are the factors of a quadratic equation, then 'a' and 'b' are its roots.

Multiply (x + 3) and (x - $\frac{3}{2}$ to see that this indeed is the given quadratic equation.

5 0

3 years ago

Can you pleaseee help meee

Mrac [35]

Yesssssssss, with what though

6 0

2 years ago

Convert the following percent to a decimal: 56 percent.

mihalych1998 [28]

Answer:

0.56

Step-by-step explanation:

Percent means 'per 100'. So 56% means 56 per 100 or simply 56/100. If you divide 56 by 100, you'll get 0.56.

56/100 = 0.56

5 0

2 years ago

HELLLLLLLLLLPPPPPPPPPPPPPPPP NO LINKS PLZZZZZZZZZZ

melisa1 [442]

Answer:

I cant see any pictures?

Step-by-step explanation:

7 0

3 years ago

Suppose the waiting times in an emergency room are normally distributed with a mean (mean) of 40 and a standard deviation (sigma

kipiarov [429]

Answer:

0.68269

Step-by-step explanation:

When we are to find the z score for population where a random sample is picked, the z.score formula we use is

z = (x-μ)/Standard error, where

x is the raw score,

μ is the population mean

Standard error = σ/√n

σ is the population standard deviation

n = random number of samples

For : x = 38 minutes, μ = 40, σ = 10, n = 5

z = 38 - 40/10 /√25

= -2/10/5

= -2/2

= -1

Determining the probability value using z table

P(x = 38) = P(z = -1)

= 0.15866

For : x = 42 minutes, μ = 40, σ = 10, n = 25

z = 42 - 40/10 /√25

= 2/10/5

= 2/2

= 1

Determining the probability value using z table

P(x = 42) = P(z = 1)

= 0.84134

The probability that their average waiting time will be between 38 and 42 minutes is calculated as

P(-Z<x<Z)

= P(-1 < x < 1)

= P(z = 1) - P(z = -1)

= 0.84134 - 0.15866

= 0.68269

Therefore, the probability that their average waiting time will be between 38 and 42 minutes is 0.68269

3 0

3 years ago