It is asking you to substitute or plug in the values.
Example:
Evaluate 3r(s+3) if r = -3 and s = 5
See that r? It means that you put in -3 in place of the r, and you put 5 in place of the s so it looks like this:
3*-3(5+3)
Now solve that using order of operations and you should get
-9*(5+3) (don't forget that your'e distributing here FIRST then add)
-45+-27
-72
That's how you solve an expression like that. This is only an EXAMPLE. Hope it helped.
Answer:
8. parallel
9. not parallel
Step-by-step explanation:
Segment ST will be parallel to base segment PR if the sides of the triangle are divided proportionally.
<h3>8.</h3>
We can compare the whole to the short part:
102/45 ?? (41.8 +33)/33
2.266... = 74.8/33 = 2.266...
The sides are proportional, so the segments are parallel.
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<h3>9.</h3>
We can compare the longer portion to the shorter portion.
38/19 ?? 52/24
2 ≠ 2 1/6
The sides are not proportional, so the segments are not parallel.
_____
<em>Additional comment</em>
Here, we compared segment lengths on the same side of the triangle. You can also compare segment lengths on opposite sides of the triangle. For example, in 9, you could look at any of the relations ...
19/24 vs 38/52
19/(19+38) vs 24/(24+52)
or the inverse of these:
24/19 vs 52/39, for example
Using the Newton's law of cooling, the time it takes to cool to 100°F is 116 mins.
<h3>Newton's law of cooling</h3>
According to the Newton's law of cooling, the when an object is exposed to the surrounding it looses heat rapidly untill it is at a thermal equilibrium with the suurroundings.
Now;
T(t) = T(s) + (To - Ts)e^-kt
T(t) = temperature at time T
To = initial temperature
Ts = temperature of the surrounding
k = colling constant
t = time taken
200 = 68 + (230 - 68)e^-15k
200 = 68 + 162e^-15k
200 - 68/162 = e^-15k
ln(0.815) = -15k
k = ln(0.815)/-15
k = 0.014 min-1
Now;
100 = 68 + (230 - 68)e^-( 0.014t)
100 -68/162 = e^-( 0.014t)
0.198 =e^-( 0.014t)
ln(0.198) = -( 0.014t)
t = ln(0.198)/-0.014
t = 116 mins
Learn more about newtons law of cooling: brainly.com/question/14643865: