Plug in the first equation into the he second equation
3x-(2x+7)=-9
3x-2x-7=-9
x-7=-9
x=-2
plug in x=-2 into the first equation
y=2(-2)+7
y=-4+7
y=3
answer: (-2,3)
The answer would be each pair of sandals costed $14
$14+$14=28+$3=$31
<h3>
Answer: (-infinity, 7]</h3>
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Explanation:
The first interval (-infinity, 3) describes any number less than 3, so we can write x < 3 in short hand (where x is the unknown number).
The second interval (-1, 7] means we start at -1 and stop at 7. We do not include -1 but include 7. So we say that
(ie x is between -1 and 7; exclude -1, include 7)
If you were to graph each ona number line, you would see that the too intervals have overlapping parts. The right most edge extends out as far as x = 7. There is no left most edge as it goes onforever that direction.
Therefore, the to intervals combine to get
which turns into the interval notation answer of (-infinity, 7]
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It might help to think of it like this: x < 3 and
say "x is some number that is less than 3, or it is between -1 and 7". So x could be anything less than 7, including 7 itself.
There are about 88 chairs in all.
All you have to do is 22x4 which equals 88. :)