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3 years ago

3x+3y=6 and 5x-6y=15

1 answer:

7 0

Multiply first equaton by 2 and add to the other equation

6x+6y=12
5x-6y=15 +
11x+0y=27

11x=27
divide both sides by 11
x=27/11

sub back
3x+3y=6
divide both sides by 3
x+y=2
(27/11)+y=2
2 and 5/11+y=2
minus 2 and 5/11 both sides
y=-5/11

x=27/11
y=-5/11
(27/11,-5/11)

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Perform the following division:

Radda [10]

Hey!

Alright, the first step to solving this division problem would be to convert the mixed fraction into a simple fraction. To do that, we'll multiply the denominator by the whole number and then add that total to the numerator.

Original Fraction :
$3 \frac{3}{4}$

New Fraction {Changed by Conversion} :
$\frac{15}{4}$

Now that we've successfully done that we'll have to change the equation.

Old Equation :
$\frac{15}{4}$ ÷ $\frac{2}{8}$ = ?

New Equation {Changed by Flipping the Second Fraction and the Symbol} :
$\frac{15}{4}$ · $\frac{8}{2}$ = ?

Now we multiply straight across.

Old Equation :
$\frac{15}{4}$ · $\frac{8}{2}$ = ?

Solved :
$\frac{120}{8}$

Almost done!
Now we have to simplify the fraction.

Old Fraction :
$\frac{120}{8}$

New Fraction {Changed by Simplification} :
$\frac{15}{1}$

Now just convert it to a whole number by removing the fraction line and the number, and that's it!

So, $3 \frac{3}{4}$ ÷ $\frac{2}{8}$ equals 15.

Hope this helps!

- Lindsey Frazier ♥

7 0

3 years ago

Find the rational number of 1.2÷0.5

Dima020 [189]

$1.2 \div 0.5 = 2.4$

3 0

3 years ago

Pleaseee helpppp last question

kap26 [50]

Answer: y=-4x-3

Step-by-step explanation:

just draw all the lines on a graph

8 0

3 years ago

An FM radio station broadcasts at 84 megahertz (MHz). What is the energy of each photon in Joule? Use h = 6.6 * 10 ^ (- 34) * j

iragen [17]

Answer:

$E=5.544*10^{-26} J$

Step-by-step explanation:

The equation for photon energy is given by:

$E=hf$

Where:

$h=Planck\hspace{3}constant=6.6*10^{-34} \\f=Frequency\hspace{3}of\hspace{3}the\hspace{3}wave=84000000Hz$

This equation telling us that the higher the frequency of the photon, the greater its energy. And the longer the photon wavelength, the lower its energy.

So, replacing the data provided in the previous equation:

$E=(6.6*10^{-34} )*(84000000)=5.544*10^{-26} J$

7 0

3 years ago

a collection of dimes and quarters is worth $19.85. There are 128 coins in all. How many of each type of coin are in the collect

PolarNik [594]

Number of dimes were 81 and number of quarters were 47

Solution:

Let "d" be the number of dimes

Let "q" be the number of quarters

We know that,

value of 1 dime = $ 0.10

value of 1 quarter = $ 0.25

Given that There are 128 coins in all

number of dimes + number of quarters = 128

d + q = 128 ------ eqn 1

Also given that collection of dimes and quarters is worth $19.85

number of dimes x value of 1 dime + number of quarters x value of 1 quarter = 19.85

$d \times 0.10 + q \times 0.25 = 19.85$

0.1d + 0.25q = 19.85 -------- eqn 2

Let us solve eqn 1 and eqn 2

From eqn 1,

d = 128 - q -------- eqn 3

Substitute eqn 3 in eqn 2

0.1(128 - q) + 0.25q = 19.85

12.8 - 0.1q + 0.25q = 19.85

12.8 + 0.15q = 19.85

0.15q = 7.05

Therefore from eqn 3,

d = 128 - q

d = 128 - 47

Thus number of dimes were 81 and number of quarters were 47

4 0

3 years ago