a) 2^(x+3)= 4^(2x)
make base number the same
2^(x+3)= 2^2 (2x)
set the exponents equal to eachother
x+3=2 (2x)
x+3=4x
-x both sides
3=3x
÷3 both sides
x=1
b) 16^(1/5)×2^(x)=8^(3/4)
make base same number
2^4 (1/5)×2^(x)=2^3 (3/4)
2^(4/5)×2^(x)=2^(9/4)
set exponents
4/5 +x=9/4
-4/5 both sides
x= 29/20