On comparing the ratios of the coefficients, find out whether the pair of
equations x - 2y =0 and 3x + 4y -20 =0 is consistent or inconsistent
Answers
Answer :
Consistent
Note:
★ A linear equation is two variables represent a straight line .
★ The word consistent is used for the system of equations which consists any solution .
★ The word inconsistent is used for the system of equations which doesn't consists any solution .
★ Solution of a system of equations : It refers to the possibile values of the variable which satisfy all the equations in the given system .
★ A pair of linear equations are said to be consistent if their graph ( Straight line ) either intersect or coincide each other .
★ A pair of linear equations are said to be inconsistent if their graph ( Straight line ) are parallel .
★ If we consider equations of two straight line
ax + by + c = 0 and a'x + b'y + c' = 0 , then ;
• The lines are intersecting if a/a' ≠ b/b' .
→ In this case , unique solution is found .
• The lines are coincident if a/a' = b/b' = c/c' .
→ In this case , infinitely many solutions are found .
• The lines are parallel if a/a' = b/b' ≠ c/c' .
→ In this case , no solution is found .
Solution :
Here ,
The given equations of lines are :
x - 2y = 0
3x + 4y - 20 = 0
Clearly , we have ;
a = 1
a' = 3
b = -2
b' = 4
c = 0
c' = -20
Now ,
a/a' = 1/3
b/b' = -2/4 = -1/2
c/c' = 0/-20 = 0
Clearly ,
a/a' ≠ b/b'