z varies inversely with the product of x and y. when x=2 and y=4, z=0.5. what is the value of z when x=4 and y=9? please help, i've tried different things and i can't seem to get the correct answer. my choices are a: 45/2 b: 40/9 c:40 d: 1/9
If z varies inversely with the product of x and y: z = k/ (x*y) 0.5 = k/(2*4) 0.5 = k/ 8 k = 0.5 * 8 k = 4. Therefore, when x = 4 and y = 9: z = 4 / (4*9) = 4/36 = 1/9 Answer: D ) 1/9
