TS EAMCET 18-July-2022 Shift 2 Solved Paper

Given, equation of pair of lines
‌5x2+‌

40

3

xy+ky2=0
⇒k(‌

y

x

)2+‌

40

3

(‌

y

x

)+5=0.
Here, y∕x=3 satisfies the equation
∴‌‌9k+40+5=0⇒k=−5
∴ Pair of straight line is 5x2+‌

40

3

xy−5y2=0
As coefficients of x2 and y2 are negative of each other, so angle between the lines is right angle.