Question

If (a + 1, a – 1) is a solution of equation $4x+3y=1$ and (b + 2, b – 2) is a solution of equation $2x–5y=6$, then the value of $\frac{b}{a}$ is

• A. $\frac{3}{8}$
• B. $\frac{8}{3}$
• C. Undefined
• D. 0

Answer 1

The correct option is C Undefined

Given that (a + 1, a – 1) is a solution of 4x + 3y = 1 and (b + 2, b – 2) is a solution of 2x – 5y = 6.
Substituting x = a + 1 and y = a – 1 in 4x + 3y = 1, we get
4(a + 1) + 3(a – 1) = 1
$\Rightarrow 4a+4+3a–3=1$
$\Rightarrow 7a+1=1$
$\Rightarrow 7a=0$
$\Rightarrow a=0$
Substituting x = b + 2 and y = b – 2 in 2x – 5y = 6, we get
$2(b+2)-5(b-2)=6$
$\Rightarrow 2b+4-5b+10=6$
$\Rightarrow -3b=6-14=-8$
$\Rightarrow b=\frac{8}{3}$
$\therefore \frac{b}{a}=\frac{\frac{8}{3}}{0}$ (Undefined)
Hence, the correct answer is option (c).