更新1:
i used -(-23)^2 instead of -(-23) and i correctly wrote the formula! Damn i need some rest Thank you guys!
Solve this equation?
回答 (4)
2016-08-02 4:42 pm
Use formula :
For ax² + bx + c = 0
x = [-b ± √(b² - 4ac)] / (2a)
x² - 23x + 81 = 0
x = {-(-23) ± √[(-23)² - 4*1*81]} / (2*1)
x = (23 + √205)/2 or x = (23 - √205)/2
For ax² + bx + c = 0
x = [-b ± √(b² - 4ac)] / (2a)
x² - 23x + 81 = 0
x = {-(-23) ± √[(-23)² - 4*1*81]} / (2*1)
x = (23 + √205)/2 or x = (23 - √205)/2
2016-08-02 4:42 pm
Solve Quadratics by
Factoring,
Completing the Square, or
Quadratic Formula x = -b/2a ±√(b² -4ac)/2a (written as the vertex ± intercept offsets)
In this case, plug it into the QF, it has 2 Real answers.
Factoring,
Completing the Square, or
Quadratic Formula x = -b/2a ±√(b² -4ac)/2a (written as the vertex ± intercept offsets)
In this case, plug it into the QF, it has 2 Real answers.
2016-08-02 4:42 pm
x=23/2 +/- √[23² -4*81] /2
x=23/2 +/- √205 /2≈ 4.34, 18.66
x=23/2 +/- √205 /2≈ 4.34, 18.66
2016-08-02 4:40 pm
x = (23 +/- sqrt((-23)^2 - 4 * 1 * 81)) / (2 * 1)
x = (23 +/- sqrt(529 - 324)) / 2
x = (23 +/- sqrt(205)) / 2
x = (23 +/- sqrt(529 - 324)) / 2
x = (23 +/- sqrt(205)) / 2
收錄日期: 2021-04-20 16:26:10
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20160802083622AA8CMYw