中等math-u04-d03
y varies inversely as x. Given that y = 6 when x = 4, the value of y when x = 8 is:
A. 3✓ 答案
B. 12
C. 2
D. 6
解說
Inverse variation gives xy = k, so k = 4 x 6 = 24. When x = 8, y = 24/8 = 3. Since x doubled, y halved.
Inverse variation gives xy = k, so k = 4 x 6 = 24. When x = 8, y = 24/8 = 3. Since x doubled, y halved.