Answer:
13.5 minutes
Step-by-step explanation:

Cross multiply
3 × 576 = 128x
3 × 576 = 1,728
1,728 = 128x
1,728 ÷ 128 = x
13.5 = x
Got two types of info here $ and #buttons
Line them accordingly and then cross multiply
a.
$18/12 dozen buttons =
$ x /4 dozen buttons
X= 4•18/12= $6
b.
$18/12 dozen buttons =
$ x/50 dozen buttons
X=18•50/12= $75
c.
$18/12 dozen buttons =
$27/x dozen buttons
X=27•12/18=18 dozen buttons
I wrote my decision on a piece of paper.
Answer:

Step-by-step explanation:
There is nothing to solve. Perhaps you want to simplify the expression.

_____
The applicable rules of exponents are ...
b^-1 = 1/b
(a^b)(a^c) = a^(b+c)
r^2=-0.32
in order to remove the square, you need to find the square root of -0.32
r^2=-0.32
r