solve this simultaneous urgentl please! x^2-y^2 =40.....(1) and x+) =10.....(ii)?
回答 (2)
2016-11-21 2:46 am
x² - y² = 40
⇒ (x+y)(x-y) = 40
⇒ 10(x-y) = 40
⇒ x-y = 4
[1] x+y = 10
[2] x-y = 4
[1]+[2]: 2x = 14 ⇒ x = 7 ⇒ y = 3
So x = 7, y = 3.
[PSA: Don’t forget to award best answer and reclaim 3 easy points!]
⇒ (x+y)(x-y) = 40
⇒ 10(x-y) = 40
⇒ x-y = 4
[1] x+y = 10
[2] x-y = 4
[1]+[2]: 2x = 14 ⇒ x = 7 ⇒ y = 3
So x = 7, y = 3.
[PSA: Don’t forget to award best answer and reclaim 3 easy points!]
2016-11-20 12:02 am
x = 7, y = 3
收錄日期: 2021-04-23 23:52:25
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