Let's set up two equations:
x+y=20 We know she brought total of 20, some of each so x=small y=big
20x+ 30y=450
x+y= 20
-y -y
------------
x= 20 -y
substitute into the other equation:
20 (20-y) + 30y = 450
400 - 20y + 30y = 450
400+ 10 y = 450
10 y = 50
y= 5
So she brought 5 big cases. Then substitute the value of y into one of the equations.
5+ x = 20
x= 15
So we bought 15 small cases and 5 big cases.
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Answer:
The expression: x + 3x + (3x-5)
Step-by-step explanation:
Okay, so x is the amount of $ spent. And three times means 3x, and 5 less on entertainment is 3x - 5. So put the expression together and you get x + 3x + (3x-5). Now plug in 10 for x so 10+3(10) + (3(10) -5).
B. $30
C. $25
D. $65
Half-life = [elapsed time * log (2)] / [log (begng amt / endg amt)]
half-life = (3 days * 0.30102999566) / log (1 / .58)
<span>half-life = 0.903089987 / log </span>
(<span>
<span>
<span>
1.724137931)
</span></span></span>half-life = <span>0.903089987 / 0.23657200643</span>
half-life =
<span>
<span>
<span>
3.8174 days
Source:
http://www.1728.org/halflife.htm
</span></span></span>
Answer:
(2x+3)*(x+3)
Step-by-step explanation:
