To find f(-20), first figure out which piece x = -20 fits with.
Since -20 < -12, x = -20 first in the domain used by the third piece.
For f(-20), treat this function as if it was just f(x) = 3x-7.
f(-20) = 3(-20) -7
= -60 - 7
= -67
The mathematical sentence can be written as:
x^3 = y^5
<h3>
How to write the expression?</h3>
A number a to the power of n is written as:
a^n
Then:
"x to the power of 3 is equal to y to the power of 5"
Would be written as:
x^3 = y^5
Particularly, this does not appear in the given options, but this is the correct and simplest way of writing the given mathematical sentence.
If you want to learn more about expressions, you can read:
brainly.com/question/4344214
Standard formula for arithmetic sequence:
an = a0 + d(n-1)
if we use the two terms given, setting a12 as starting term and a45 as the end term an.
170 = 38 + 33d
170 - 38 = 33d
132 = 33d
132/33 = d
This is the common difference, use it to find the first term.
38 = a0 + (132/33)(12-1)
38 = a0 + (132/33)(11)
38 = a0 + 132/3
38 - 132/3 = a0
38 - 44 = a0
-6 = a0
The starting term is -6
