what is a if a^2 + (2a)^2 = 225 ?
回答 (5)
2009-02-16 9:11 am
✔ 最佳答案
a^2 + (2a)^2 = 225a^2 + (2^2)(a^2) = 225
a^2 + 4a^2 = 225
5a^2 = 225
a^2 = 225/5
a^2 = 45
a = ±√45
a = ±√(3^2 * 5)
a = ±3√5
2009-02-16 4:03 pm
a² + (2a)² = 225
a² + 4a² = 225
5a² = 225
a² = 45
a = â45
Answer: a = â45 OR 6.7082039
Proof:
6.708204² + (2[6.708204])² = 225
45 + 13.416407² = 225
45 + 180 = 225
225 = 225
a² + 4a² = 225
5a² = 225
a² = 45
a = â45
Answer: a = â45 OR 6.7082039
Proof:
6.708204² + (2[6.708204])² = 225
45 + 13.416407² = 225
45 + 180 = 225
225 = 225
2009-02-16 4:22 pm
a^2+(2a)^2=225
a^2+4a^2=225
5a^2=225
a^2=45
a=+/-sqrt(45)
a=+/-sqrt(9*5)
a=+/-3sqrt(5) answer//
a^2+4a^2=225
5a^2=225
a^2=45
a=+/-sqrt(45)
a=+/-sqrt(9*5)
a=+/-3sqrt(5) answer//
2009-02-16 4:08 pm
+/- 6.7082
2009-02-16 3:58 pm
a^2 + (2a)^2 = 225. Remember you need to square both the 2 and the a.
a^2 + 4a^2 = 225. Collect like terms.
5a^2 = 225. Divide by 5.
a^2 = 45 Take the square roots (plus and minus).
a = +/- 3 sqrt 5
a^2 + 4a^2 = 225. Collect like terms.
5a^2 = 225. Divide by 5.
a^2 = 45 Take the square roots (plus and minus).
a = +/- 3 sqrt 5
收錄日期: 2021-05-01 12:02:30
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20090215235145AAqyktZ