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3 years ago

Solve the system using elimination 2x+3y=8 5x+6y=17

Mathematics

1 answer:

UNO [17]3 years ago

6 0

Answer:

x=1

Step-by-step explanation:

For this problem, we can choose to eliminate either the x values or the y values.

In this case, it would be easier to do y.

We alter the first equation by multiplying by -2 on both sides.

-4x+-6y=-16

Now, we have the equations

-4x+-6y=-16 and 5x+6y=17.

We can see that there is -6y in one equation and 6y in the other, meaning that if we add both equations together, the ys will cancel each other out because they are opposites.

So let's add the equations.

-4x-6y+5x+6y=-16+17

x=1

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Nirmala graphed the relationship between the duration (in hours) of using an oil lamp and the volume (in milliliters) of oil rem

mariarad [96]

Answer:

Nirmala can use the lamp for 31.66 hours before it runs out of oil.

Step-by-step explanation:

From the graph,

Take any two points, let say

(15, 25)

(25, 10)

$\mathrm{Slope\:between\:two\:points}:\quad \mathrm{Slope}=\frac{y_2-y_1}{x_2-x_1}$

$\left(x_1,\:y_1\right)=\left(15,\:25\right),\:\left(x_2,\:y_2\right)=\left(25,\:10\right)$

$m=\frac{10-25}{25-15}$

$m=-\frac{3}{2}$

The equation of line in slope-intercept form

$y = mx + b$

Putting $m=-\frac{3}{2}$ and any point, let say (25, 10), to find the y-intercept 'b'

$10=-\frac{3}{2}\left(25\right)+b$

$-\frac{3}{2}\left(25\right)+b=10$

$-\frac{75}{2}+b=10$

$\mathrm{Add\:}\frac{75}{2}\mathrm{\:to\:both\:sides}$

$-\frac{75}{2}+b+\frac{75}{2}=10+\frac{75}{2}$

$b=\frac{95}{2}$

$b=47.5$

So the equation of line will be:

$y = mx + b$

$y=-\frac{3}{2}x+47.5$

In order to find how long Nirmala can use the lamp before it runs out of oil, we need to find x-intercept which can be obtained by putting y = 0, and solve for x, as duration lies on x-axis.

$y=-\frac{3}{2}x+47.5$

Putting y = 0

$0=-\frac{3}{2}x+47.5$