Question

please help me in no. 20​

Answer 1

Answer:

(b) 2/3 < x < 7/5

Step-by-step explanation:

15x² - 31x + 14 < 0

<=> ( 3x - 2 ) ( 5x - 7 ) < 0

and this happens when one of the factors is positive and the other is negative.

Now

3x-2 < 0 <=> x < 2/3

and

5x-7 < 0 <=> x < 7/5.

So:

• for x < 2/3, both factors are negative;
• for x > 7/5, both factors are positive;
• for 2/3 < x < 7/5, one factor is positive and the other is negative.