All categories

3 years ago

Can someone help me with the first 3 as it is my first time doing it ? I need help

Mathematics

1 answer:

Fed [463]3 years ago

7 0

You problem is you don't have any problem. You have a bunch of formulas for the perimeter and area of some shapes.

As for using the formulas, usually you're given all but one of the variables and you can solve for the remaining one.

Notice how the triangle result doesn't have area as a function of a, b and c. That's called Heron's formula and is usually not taught to secondary school students. I don't like to teach it either because Archimedes' Theorem is so much better:

The sides a,b,c and area S of a triangle satisfy

$16S^2 = (a+b+c)(-a+b+c)(a-b+c)(a+b-c) = 4a^2b^2-(c^2-a^2-b^2)^2 = (a^2+b^2+c^2)^2 - 2(a^4+b^4+c^4)$

You might be interested in

In a class there are 15 students. 8 of them like playing soccer, 6 of them like swimming, and 2 like both and swimming and playi

xenn [34]

Answer:

6+8-2=12, 15-12=3 answer=3

5 0

2 years ago

The ratio of the geometric mean and arithmetic mean of two numbers is 3:5, find the ratio of the smaller number to the larger nu

IgorC [24]

Answer:

$\frac{1}{9}$

Step-by-step explanation:

Let the numbers be x,y, where x>y

The geometric mean is

$\sqrt{xy}$

The Arithmetic mean is

$\frac{x + y}{2}$

The ratio of the geometric mean and arithmetic mean of two numbers is 3:5.

$\frac{ \sqrt{xy} }{ \frac{x + y}{2} } = \frac{3}{5}$

We can write the equation;

$\sqrt{xy} = 3$

$xy = 9 - - - (2)$

and

$\frac{x + y}{2} = 5$

$x + y = 10 - - - (2)$

Make y the subject in equation 2

$y = 10 - x - - - (3)$

Put equation 3 in 1

$x(10 - x) = 9$

$10x - {x}^{2} = 9$

${x}^{2} - 10x + 9 = 0$

$(x - 9)(x - 1) = 0$

$x =1 \: or \: 9$

When x=1, y=10-1=9

When x=9, y=10-9=1

Therefore x=9, and y=1

The ratio of the smaller number to the larger number is

$\frac{1}{9}$

3 0

3 years ago

1. Refer to the equation 2x − 6y = 12. (a) Create a table of values for at least 4 points. Show your work.

Sergio039 [100]

2x - 6y = 12

so we pick any number for x and then solve for y

lets say x = 0
2(0) - 6y = 12
-6y = 12
y = -12/6
y = -2....so when x = 0, y = -2....(0,-2) <== one point

lets say x = 1
2(1) - 6x = 12
2 - 6x = 12
-6x = 12 - 2
-6x = 10
x = -10/6
x = - 5/3...so when x = 1, y = -5/3....(1,-5/3) <== another point

Lets say x = 2
2(2) - 6y = 12
4 - 6y = 12
-6y = 12 - 4
-6y = 8
y = -8/6
y = - 4/3....so when x = 2, y = -4/3.....(2,-4/3) <== another point

lets say x = 3
2(3) - 6y = 12
6 - 6y = 12
-6y = 12 - 6
-6y = 6
y = -6/6
y = -1....so when x = 3, y = -1.....(3,-1) <== another point

now there is 4 points.

4 0

3 years ago

Point Lis a centroid of the triangle FWD, If RL = 54 cm, what is RD?

Wittaler [7]

Answer:

RD = 162 cm

Step-by-step explanation:

LD = 2 RL = 2* 54 = 108

RD = RL + LD

RD = 54 + 108

RD = 162 cm

7 0

3 years ago

10 + 2 = 12 12 − 2 = 10 What are these operations called? Transverse operations Reverse operations Divided operations Inverse op

jeka57 [31]

Inverse operations are operations that undo each other.
In this case, 10 + 2 = 12, and 12 - 2 = 10
A multiplication example could be 4 x 2 = 8, and 8 ÷ 2 = 4

Answer is inverse operations.

3 0

3 years ago

Read 2 more answers