Question

Solve the system by graphing. Write the solution as an ordered pair. y = 1/3x + 2 y = –x – 2

Answer 1

ANSWER

The solution is where the two graphs intersect, which is
$(-3,1).$

EXPLANATION

The given system of equations are
$y = \frac{1}{3} x + 2$
and

$y = - x - 2$

We need to graph the two equations.

Let us graph

$y = \frac{1}{3} x + 2$
first.

We need at least two points.

You can choose any appropriate value for x and solve for y. Choosing zero makes our working easier. So let us plot the intercepts.

When
$x = 0$

$\Rightarrow \: y = \frac{1}{3} (0) + 2$

$\Rightarrow y = 0 + 2$

$\Rightarrow y = 2$

So this gives us the ordered pair,

$(0,2)$

When
$y = 0$
we get,

$0= \frac{1}{3} x + 2$

$\Rightarrow \: - 2 = \frac{1}{3} x$

$\Rightarrow \: - 2 \times 3= x$

$\Rightarrow \: -6= x$
This also gives the ordered pair

$(-6,0).$

We plot these two points and draw a straight line through them to obtain the blue graph in the attachment.

For the second line

$y = - x - 2$

We again find the intercepts and plot them.

When
$x = 0$

$y = - 0 - 2$

$\Rightarrow \: y = - 2$

This gives the ordered pair

$(0,-2)$

Also, when
$y = 0$

then we have,

$0 = - x - 2$

$2 = - x$

$x = - 2$

Then we again have the ordered pair,

$(-2,0)$

We plot these two points on the same graph sheet to obtain the red graph above.

The intersection of the two lines is
$(-3,1)$


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