1a)Solve 4x^2-17x+15=0 by the quadratic formula
b)Using the results of (a).solve 4(y+1)^2-17(y+1)+15=0
2a)12x^2-16kx+5k^2=0 is a quadratic equation in x where k is an interger.It is given that 3/2 is a root of the equation.By using the quadratic formula,find
a)the value of k,
b)the other root of the equation.
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請問呢2條數點做?
2012-09-01 8:55 am
回答 (2)
2012-09-01 5:50 pm
✔ 最佳答案
1(a) x = {17 + √[17^2 - 4(4)(15)]}/2(4) or x = {17 - √[17^2 - 4(4)(15)]}/2(4)x = 3 or 5/4(b) y + 1 = xSo, y + 1 = 3 or 5/4y = 2 or 1/42(a) x = {16k + √[(16k)^2 - 4(12)(5k^2)]}/2(12) or x = {16k - √[(16k)^2 - 4(12)(5k^2)]}/2(12)x = 5k/6 or x = k/2As k is an integer, k should be 3(b) The other root is 5k/6 = 15/6 = 5/2 
2012-09-01 3:18 pm
The formula of the quadratic equation:
圖片參考：http://imgcld.yimg.com/8/n/HA00100646/o/701209010003313873365260.jpg
1.
a)Substituting values into the formula,
圖片參考：http://imgcld.yimg.com/8/n/HA00100646/o/701209010003313873365261.jpg
x=3 or 5/4
b) Let y+1=x
Therefore, y+1=3 or y+1=5/4
y=2 or 1/4
第二題唔識
圖片參考：http://imgcld.yimg.com/8/n/HA00100646/o/701209010003313873365260.jpg
1.
a)Substituting values into the formula,
圖片參考：http://imgcld.yimg.com/8/n/HA00100646/o/701209010003313873365261.jpg
x=3 or 5/4
b) Let y+1=x
Therefore, y+1=3 or y+1=5/4
y=2 or 1/4
第二題唔識
參考: me
收錄日期: 2021-04-20 13:18:09
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https://hk.answers.yahoo.com/question/index?qid=20120901000051KK00033