\begin{aligned} 7.5+k& =10 7.5+k-7.5& =10-7.5& \green{\text{step } 1} k& =2.5& \blue{\text{step } 2} \end{aligned}
7.5+k
7.5+k−7.5
k


=10
=10−7.5
=2.5


step 1
step 2


find annie's mistake.
choose 1
choose 1

(choice a)
a
\green{\text{step }1}step 1start color #28ae7b, start text, s, t, e, p, space, end text, 1, end color #28ae7b

(choice b)
b
\blue{\text{step }2}step 2start color #6495ed, start text, s, t, e, p, space, end text, 2, end color #6495ed

(choice c)
c
annie did not make a mistake.

since your problem is x^4 = 81, what you have to undeo is the "to the fourth power" part.

the inverse (opposite operation) of "to the fourth power" is "to the fourth root".

  (x^4) ^ ¼   = 81 ^ ¼  

  81 = 3^4     so (3 ^ 4) ^ ¼   =   3 ^ 1   = 3

by hand: (3 ^ 4) ^ ¼   =   3 ^ (4 x ¼) = 3 ^ 1   = 3   (when you take a power to a power, multiply the exponents.)

or, do it by calculator. one way of finding the fourth root is to use ^ (1/4)

step-by-step explanation:

answer

106 emergencies

step-by-step explanation:

3

step-by-step explanation: