What do the terms scale and interval mean in reference to a line graph

Consider the function f(x)=-5x+3 what is f(-2)

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

A(1,1) b(-3,0) c(-4,-1) d(3,-2) drag it to correct position