I need help with these. But just answer a comfortable amount. You can answer just one, two or all three. But it's urgent. I'm in need of help.

x=16 and 6.7

Explanation:
Sqrt (3x + 1) -7=0
Sqrt 3x + 1 = 7
3x + 1 = 49 (square both sides to get rid of radical)
3x = 49-1
x = 48/3 = 16

67 • 0.6^x
When you are multiplying with number less than 1 the number decrease
If x was 2 then 67 • 0.6^2 = 67 x 0.36
If x was 3 then 67 x 0.216
If x was 4 then 67 x 0.129 approximately 67 x 0.1 = 6.7