Answer:
A book is worth $1 and a DVD is worth $12.
Step-by-step explanation:
The equations (2 unknowns and two equations, d is for a DVD and b is for a book):
For David: 3d+4b=40
For Anna: d+6b=18
Now multiply the second equation with -3 and add to the first equation:
3d+4b=40
−3d−18b=−54
Combined equation: −14b=−14 and b=1 (means that each book is worth $1).
Now for DVD price, use the second equation:
d=18−6 or d=12 (means that each DVD is worth $12).
A book is worth $1 and a DVD is worth $12.
A word to the wise: It's <span> f(x)=125(0.9)^x, where ^ represents exponentiation.
In this case the ave. value over the interval [11, 15] is
125(0.9)^15 - 125(0.9)^11
------------------------------------- = (125/4) [ 0.9^15 - 0.9^11)
15 - 11 = (31.25) [ 0.2059 - 0.3138 ] = a negative result
= (31.25)(-0.1079) = -3.372 (av. r. of c.
over the interval [11,15] )
Do the same thing for the time interval [1,5]. Then compare the two rates of change.</span>
The answer is "$94."
If all 6 friends spent $420 on kayaks, and $144 on food, then they spent $564 in total. Divide $564 by 6 people to see how much each person payed.
420+144=564
564÷6=94
F(x) = 9x²<span> - 5x + 2
</span>f(-2) = 9(-2)² - 5(-2) + 2
<span>f(-2) = 36 + 10 + 2
</span><span>f(-2) = 48</span>
Answer: See explanation
Step-by-step explanation:
1. Cost = $413
Sales percent = 6.5%
Cost of bike = $413 + (6.5% × $413)
= $413 + (0.065 × $413)
= $413 + $26.845
= $439.85
2. Cost of dishwasher = $569
Commission rate = 18%
The expression for the commission will be:
= 18% × $569
= 18/100 × $569
= 0.18($569)