Been stuck on this one for hours, absolutely no clue how to solve.
Suppose z varies jointly with x and y. If z = -180 when y = 15 and x = -3, then find z when x = 7 and y = -5. *
Joint Variation?
2020-04-08 12:58 am
回答 (1)
2020-04-08 1:03 am
z varies jointly with x and y, i.e. z ∝ xy
Hence, z = kxy, where k is a non-zero constant.
When y = 15 and x = -3, z = -180:
-180 = k(15)(-3)
k = 4
Hence, z = 4xy
When x = 7 and y = -5:
z = 4(7)(-5)
z = -140
Hence, z = kxy, where k is a non-zero constant.
When y = 15 and x = -3, z = -180:
-180 = k(15)(-3)
k = 4
Hence, z = 4xy
When x = 7 and y = -5:
z = 4(7)(-5)
z = -140
收錄日期: 2021-04-18 18:26:25
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20200407165800AAteelN