Solve. 7^x – 5 = 7^4x + 7

A)x = –4

B) x = -12/5

C)x = 2/3

D) x = 4

x = negative 12 over 5

x = 2 over 3

x = 4

Question

Solve. 7^x – 5 = 7^4x + 7 

 
A)x = –4 


B) x = -12/5 


 C)x = 2/3 

D) x = 4 



 x = negative 12 over 5 

 x = 2 over 3 

 x = 4

nurali · Answer

7x-5=4x+7
7x-4x = 7+5 =12
3x =12
x =12/3 = 4

whpalmer4 · Answer

Is that supposed to be
$$7^{x-5} = 7^{4x+7}$$?

You really need to take the order of evaluation into account if you aren't going to write your problems with the equation editor.  What you wrote is$$7^x-5 = 7^{4x}+7$$which is an entirely different problem.

whpalmer4 · Answer

If the problem is as I asked, then you can simply solve
$$x-5=4x+7$$ to get your answer, because the bases on both sides are equal.

whpalmer4 · Answer

@Nurali's solution is for an entirely different problem.