Answer:
x=ln(61)/ln(4)
Step-by-step explanation:
4^x+3=64
4^x=64-3
4^x=61
x=ln(61)/ln(4)
2.2 = 1.4d + 3.7 - 5.4d = 3.7 - 4d
4d = 3.7 - 2.2 = 1.5
d = 1.5/4 = 0.375