Can someone please help me with this since it been online I haven't been paying attention I know not smart of me but I will if you explain how this stuff is too confusing and I don't quite understand it.

If f(x)=3x+1 and f^-1=x-1/3, then f^-1(7)=

X-intercept=-5 y-intercept=2 the equation of the line is

A33 gram sample of a substance that's used to detect explosives has a k-value of 0.1473. n = noekt no = initial mass (at time t = 0) n = mass at time t k = a positive constant that depends on the substance itself and on the units used to measure time t = time, in days