Find the value of $x$ and $y$ using cross multiplication method:
$x + y = 1$ and $x - y = 3$

x = 1

y = - 1

No worries! We‘ve got your back. Try BYJU‘S free classes today!

x = 2

y = - 1

Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses

x = - 2

y = - 1

No worries! We‘ve got your back. Try BYJU‘S free classes today!

x = 2

y = 1

No worries! We‘ve got your back. Try BYJU‘S free classes today!

Open in App

Solution

The correct option is A $x = 2$ ,
$y = - 1$

$x + y = 1$ ---(1)
$x - y = 3$ ---(2)
Using formula for cross multiplication method:
$\frac{x}{(b_{1} c_{2} - b_{2} c_{1})} = \frac{y}{(c_{1} a_{2} - a_{1} c_{2})} = \frac{- 1}{(a_{1} b_{2} - a_{2} b_{1})}$
So, from equation (1) and (2) we can write the value of $a, b$ and $c$ .
$\frac{x}{(1 \times 3 - (- 1 \times 1))} = \frac{y}{(1 \times 1 - 1 \times 3)} = \frac{- 1}{(1 \times - 1 - 1 \times 1)}$
$\frac{x}{3 + 1} = \frac{y}{1 - 3} = \frac{- 1}{- 1 - 1}$
$\frac{x}{4} = \frac{y}{- 2} = \frac{- 1}{- 2}$
$\frac{x}{4} = \frac{- 1}{- 2}$
$- 2 x = - 4$
$x = 2$
$\frac{y}{- 2} = \frac{- 1}{- 2}$
$- 2 y = 2$
$y = - 1$
Therefore, $x = 2, y = - 1$

Suggest Corrections

Similar questions

Find the value of x and y from the pair of linear equations, using cross-multiplication method.

$\frac{1}{5}$ (x – 2) = $\frac{1}{4}$ (1 – y)

26x + 3y + 4 = 0

\frac{5}{(x + y)} - \frac{2}{(x - y)} + 1 = 0 \frac{15}{(x + y)} + \frac{7}{(x - y)} - 10 = 0 (x \neq y, x \neq - y)

\frac{- 1}{x} + \frac{2}{y} = 0

\frac{x}{2} + \frac{y}{3} = 1

x

y

x + y = 15

x - y = 3

Join BYJU'S Learning Program