Simplify the expression where possible. (x^2)^4

Step-by-step explanation:

According to the third law of indices,

In this case m=2 and n=4

So that can be applied thus:

2×4=8

so it will now be written this way:

x^8

5x - 9 = 2x + 23

Step-by-step explanation:

This question is asking you to take a verbal description to write an equation.  Using key words and phrases from the problem, you can set up an equation and solve for the missing variable.  

'five times a number': 5x (5 multiplied by a variable)

'decreased by 9': -9 (subtract 9)

'five times a number decreased by 9': 5x - 9

'is equal to' =

'twice the number': 2x (2 multiplied by the variable)

'increased by 23': + 23 (add 23)

'twice the number increased by 23': 2x + 23

Set the two expressions equal to each other:  5x - 9 = 2x + 23