Question 678468
1. Solve Solve 4^x = 12.
xlog4=log12
x=log12/log4
using calculator
x≈1.792
..
2. Solve 5^(x + 5)= 9^x.
(x+5)log5=xlog9
(x+5)/x=log9/log5≈1.365
x+5=1.365x
x-1.365x=-5
.365x=5
x≈13.70
..
you do the rest 
3. Solve 4^(x + 7) = 6^(x – 1). 
4. Solve 2^(x + 3) = 7