Question

Solve for x

a) log4 (x+4) - log4 (x-2) = 3
b) 4^3x = 42
c) 700(1+0.06/52)^52x = 1275

Answer 1

a) log_4(x+4)-log_4(x-2)=3

log_4((x+4)/(x-2))=3

4^(log_4((x+4)/(x-2)))=4^(3)

(x+4)/(x-2)=64

(x+4)/(64)=(x-2)

(x+4)/(64)=x-2

Least common denominator: 64

x+4=64x-128

-63x+4=-128

-63x=-132

x=44/21

Answer 2

b) 4^(3x)=42

ln(4^(3x))=ln(42)

xln(64)=ln(42)

x=ln(42)/ln(64)

x=0.8987

Answer 3

c) If your "c" is in the form
700(1+(0.06)/(52))^(5)(2x)=1275

2x=1.811

x=0.9055