Choose the correct graph of the following system of inequalities:
3x + 5y

Question

Choose the correct graph of the following system of inequalities:
3x + 5y < 10
x – 4y≤  12

zepp · Answer

Isolate y first.

anonymous · Answer

attachment

zepp · Answer

3x + 5y < 10
5y < 10-3x
y < (10-3)/5

anonymous · Answer

zepp · Answer

x – 4y≤  12
4y ≤ x-12
y ≤ (x-12)/4

anonymous · Answer

idk.how.to.do.it.on.the.graph.afta.i.isolate.the.y

zepp · Answer

@uj1024 It really doesn't..... when she's taking a test :(

zepp · Answer

Okay, we have 
$\large y < \frac{(10-3)}{5}$

and 

$\large y ≤ \frac{(x-12)}{4}$

zepp · Answer

The '<' sign indicate that the inequality doesn't include the line.

anonymous · Answer

where.the.x.go.in.the.first.one?

zepp · Answer

If we drag the slope down. We'll get: 

$\large \frac{-3x+10}{5} \rightarrow -\frac{3}{5}x+2$ Sorry, the x completely disappeared D:

zepp · Answer

and $\large \frac{x-12}{4} \rightarrow \frac{1}{4}x-3$

anonymous · Answer

ook.i.got.that.part.i.think

zepp · Answer

So we have

$\huge y<-\frac{3}{5}x+2$
and
$\huge y≤\frac{1}{4}x-3$

zepp · Answer

The first inequation's slope is negative, therefore it's going down, and the other one is going up.

anonymous · Answer

its.the.last.one.or.the.second.one.but.i.dont.understand.how.to.graph.it

zepp · Answer

Now, if y is smaller than the function itself, it mean that the shadowed zone should be all under both inequations.

zepp · Answer

|dw:1339987022164:dw|
and the function should be dotted, since it's a > sign.