7x10x and use yout braing
For number 3.
You add 8 to both sides as you need to separate the variable
4x-8=32
+8 +8
4x=32
now divide 32 by 4
x=8
for number 4
you use pemdas to multiply the parenthisis
2(x-5)=-20
(2•x)-(2•5)
2x-10=-20
then add 10 to both sides
2x-10=-20
+10 +10
2x=10
divide 10 by two
x=5
3276800/8 = 409600 (how many bacteria in an hour)
Then just multiply that number by the amount of hours you want to solve for
9 hours = 3686400
10 Hours = 4096000
I don’t speak Spanish but if you put the English trans in the comments I’d love to answer