It is okay to take the inverse of both side given that you remember to exclude the value that make the denominator zero which is in this case r=-1
Answer:

Step-by-step explanation:
we have

we know that

substitute

Answer:
13.5 meters
Step-by-step explanation:
25 / 2 = 13.5
because if a human is 3 meters tall and cast 2 times the length of himself then if a building casts 25 meters then it should be 2 times less than its shadow.
D. It is not a function because there are multiple outputs for one input.
Answer: see below
Step-by-step explanation:
3x-12=7x+8 ⇔ given
-12=4x+8 ⇔ addition property of equality
-20=4x ⇔ subtraction property of equality
x=-5 ⇔ division property of equality
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5(x-1)=4x+13 ⇔ given
5x-5=4x+13 ⇔ distributive property
x-5=13 ⇔ subtraction property of equality
x=18 ⇔ addition property of equality