All categories

3 years ago

What 4 numbers adding give you a sum of 15

Mathematics

2 answers:

goldfiish [28.3K]3 years ago

5 0

9+1+3+2= 15

Hope this helps you:)

alekssr [168]3 years ago

4 0

Answer: 6 and 9, 7 and 8. 69, 78, 87, 96. So, there are only 4 combinations which would result in 15.

Step-by-step explanation:

Therefore the average sum of three numbers is 45:3=15. The number 15 is called the magic number of the 3x3 square. You can also achieve 15, if you add the middle number 5 three times. The odd numbers 1,3,7, and 9 occur twice in the reductions, the even numbers 2,4,6,8 three times and the number 5 once.

You might be interested in

Please show your work!<br> 25% of 80

spin [16.1K]

Answer:

Step-by-step explanation:

25% change to .25

.25 x 80

Just solve 25 x 80 which equals 2000

then move decimal over twice giving you 20.00 or 20

4 0

3 years ago

Read 2 more answers

One leg of a right triangle is more than 3 more inches than the shorter leg. The hypotenuse is 15 inches. What are the lengths o

Deffense [45]

Answer:

1. 9 inches, 12 inches and 15 inches

2. 54 square inches

Step-by-step explanation:

1. The first part of this question would lead to a quadratic equation. Let the shorter leg be represented by x.

shorter leg = x

other leg = x + 3

hypotenuse = 15 inches

Applying the Pythagoras theorem, we have;

$/15/^{2}$ = $/x/^{2}$ + $/x+3/^{2}$

225 = $x^{2}$ + $(x+3)^{2}$

225 = $x^{2}$ + $x^{2}$ + 6x + 9

= 2 $x^{2}$ + 6x + 9

2 $x^{2}$ + 6x + 9 - 225 = 0

2 $x^{2}$ + 6x - 216 = 0

divide through by 2 to have

$x^{2}$ + 3x - 108 = 0

From the quadratic formula;

x = (-b ± $\sqrt{b^{2}-4ac }$ ) ÷ 2a

but, a = 1, b = 3, c = -108

x = (-3 ± $\sqrt{(3)^{2}-4(1)(-108)}$ ) ÷ 2

= (-3 ± $\sqrt{441}$ ) ÷ 2

= (-3 ± 21) ÷ 2

Thus,

x = (-3 + 21) ÷ 2 OR x = (-3 - 21) ÷ 2

x = 9 OR x = -12

So that, x = 9 inches

The shorter leg is 9 inches, and the other leg is 12 inches.

2. The area of the triangle can be determined by applying Heron's formula:

A = $\sqrt{s(s-a)(s-b)(s-c)}$

where s is the average value of the sum of the three sides a, b, and c.

Let, a = 9, b = 12 and c = 15

s = $\frac{a +b+c}{2}$

= $\frac{(9+12+15}{2}$

= 18

A = $\sqrt{18(18-9)(18-12)(18-15)}$

= $\sqrt{18*9*6*3}$

= $\sqrt{2916}$

A = 54

Area of the triangle is 54 square inches.

4 0

3 years ago

Gary needs 24 screws for every 2 chairs he builds

kicyunya [14]

Answer:

ok sooo is there something you need to be figured out orr are you just saying

Step-by-step explanation:

7 0

4 years ago

How many fixed points are there for the function<br> f(x) = x^5?

Rufina [12.5K]

Using the fixed point concept, it is found that f(x) has 3 real fixed points.

-------------------------------

The fixed points of a function f(x) are the values of x for which:

$f(x) = x$

In this question:

$f(x) = x^5$

Then

$x = x^5$

$x^5 - x = 0$

$x(x^4 - 1) = 0$

Applying subtraction of perfect squares, $x^4 - 1 = (x^2 - 1)(x^2 + 1)$

Again, $x^2 - 1 = (x - 1)(x + 1)$

Then

$x(x^4 - 1) = 0$

$x(x - 1)(x + 1)(x^2 + 1) = 0$

There are 3 real fixed points, $x = 0, x = 1$ and $x = -1$ .

A similar problem is given at brainly.com/question/22560442

3 0

2 years ago

Plssss help help help meeeeee plssss help help helppppppppppp meeeeee

Akimi4 [234]

Answer:

I think the answer for the first box is 18 and for the second box is 22. I'm not completely sure though.

4 0

3 years ago