Directly proportional, both increase/decrease, Multiple k(constant you needed to solve for)..
Inversely --one increases as the other decreases, increase the denominator & fraction gets smaller.... So
Problem:
Dirextly to X (× by X)
Inversely to Y, (÷ by Y)
Z= k X/Y
Solve, working backwards: Z =5 becomes
5 = k (X) ÷ (Y). And
X=15 and Y =9 becomes
5= k(15)/(9). Undo ÷9, ×9 both sides
45= k(15). Now undo ×15 by ÷15 both sides
45/15 = 3. So k=3, (also called your constant of variation)....and your Equation/Proportion becomes...
Z = 3X/Y
Use the new #s.... X=23, Y=14
Z= 3×23÷14 = 69/14. If they want spirochete answer divide and round to corresponding # if decimals
