JEE Main202118 Mar 2021Morning ShiftMathematicsStraight LinesActual
The number of integral values of m so that the abscissa of point of intersection of lines 3 x + 4 y = 9 and y = m x + 1 is also an integer, is:
Options
- A1
- B2
- C3
- D0
Correct answer
B. 2
Step-by-step solution
3 x + 4 y = 9 y = m x + 1 ⇒ 3 x + 4 m x + 4 = 9 ⇒ ( 3 + 4 m ) x = 5 ⇒ x will be an integer when 3 + 4 m = 5 ,   - 5 ,   1 , - 1 ⇒ m = 1 2 , - 2 , - 1 2 , - 1 so, number of integral values of m is 2