Question

For what value of k will the equations x + 5y-7= 0 and 4x + 20y + k=0 represent coincident lines?

JEE/Engineering Exams

Maths

Solution

4.0 (1 ratings)

Given equations are x +5y– 7 = 0 and 4x + 20y+k = 0 Here, d=1, b = 5 , 9 = -7 a2 = 4 , b2 = 20, C2 = k We know that equations represent coincident lines if they are consistent with many solutions. 1 -7 a1_b_ 9 1 -5--7 d2 62 C24 20k Hence, for k = -28, given equations represent coincident lines. [ k= -28