2) Which of the following quadratic equations has roots 3,5 (A) x2 - 15x + 8 =0 (C) x2 + 3x + 5 = 0 (B) x - x + 150 (D) x + 8x - 15 = 0
pls answer
Answers
Answer:
Hi ,
Substitute 3 , 5 in each quadratic equation,
if it is true then 3 ,5 are roots of that equation.
i ) x² - 15x + 8 = 0
put x = 3 ,
3² - 15 × 3 + 8 = 0
9 - 45 + 8 = 0 ( false )
ii ) x² - 8x + 15 = 0
put x = 3
3² - 8 × 3 + 15 = 0
9 - 24 + 15 = 0
24 - 24 = 0 ( True )
put x = 5 , we get
5² - 8 × 5 + 15 = 0
25 - 40 + 15 = 0
40 - 40 = 0 ( true )
Therefore 3 , 5 are roots of x² - 8x + 15 = 0
Option ( B ) is correct.
I hope this helps you.
:
Step-by-step explaHi ,
Substitute 3 , 5 in each quadratic equation,
if it is true then 3 ,5 are roots of that equation.
i ) x² - 15x + 8 = 0
put x = 3 ,
3² - 15 × 3 + 8 = 0
9 - 45 + 8 = 0 ( false )
ii ) x² - 8x + 15 = 0
put x = 3
3² - 8 × 3 + 15 = 0
9 - 24 + 15 = 0
24 - 24 = 0 ( True )
put x = 5 , we get
5² - 8 × 5 + 15 = 0
25 - 40 + 15 = 0
40 - 40 = 0 ( true )
Therefore 3 , 5 are roots of x² - 8x + 15 = 0
Option ( B ) is correct.
I hope this helps you.
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