Question

Solve the following pair of equations :

$x-y=0.9$
$\frac{11}{2(x+y)}=1$

• A. $x=1.2;y=2.3$
• B. $x=7.2;y=2.3$
• C. $x=3.2;y=2.3$
• D. $x=4.2;y=2.3$

Answer 1

Answer: (C)

$x=3.2;y=2.3$

Given, equations are $x-y=0.9$ ---- (1)
And $\frac{11}{2(x+y)}=1=>2x+2y=11$ ---- (2)
Multiplying equation $\left(1\right)$ with $2$ we get, $2x-2y=1.8$ ----- equation $\left(3\right)$

Adding
equations $1$ and $2$, we get $4x=12.8=>x=3.2$

Substituting

$x=3.2$ in the equation $\left(1\right)$, we get $3.2-y=0.9=>y=2.3$