Solve the following system of equations using the cross multiplication method.
$0.4 x + 0.3 y = 1.7 7 x - 2 y = 8$

Open in App

Solution

Step 1: Applying and Analysing
The given system of equations may be written as
$0.4 x + 0.3 y - 1.7 = 0 7 x - 2 y - 8 = 0$
The given system of equation is of the forms
$a_{1} x + b_{1} y + c_{1} = 0 a_{2} x + b_{2} y + c_{2} = 0$
Step 2: Using cross multiplication method
the equation is
$x = \frac{b_{1} c_{2} - b_{2} c_{1}}{a_{1} b_{2} - a_{2} b_{1}} y = \frac{c_{1} a_{2} - c_{2} a_{1}}{a_{1} b_{2} - a_{2} b_{1}} w h e r e, a_{1} = 0.4, b_{1} = 0.3, c_{1} = - 1.7 a_{2} = 7, b_{2} = - 2, c_{2} = - 8 S u b s t i t u t e t h e g i v e n v a l u e s i n t h e a b o v e e q u a t i o n s x = \frac{0.3 x - 8 x - x - 1.7}{0.4 x - 2 - 7 x 0.3} = \frac{2.4 - 3.4}{- 0.8 - 2.1} = \frac{- 5.8}{- 2.9} = 2 y = \frac{- 1.7 x 7 - - 8 x 0.4}{0.4 x - 2 - 7 x 0.3} = \frac{- 11.9 + 3.2}{0.8 - 2.1} = \frac{- 8.7}{- 2.9} = 3$
Hence, $x = 2$ :& $y = 3$ is the required solution.

Suggest Corrections

Similar questions

Solve each of the following systems of equations by using the method of cross multiplication:

$7 x - 2 y = 3, 22 x - 3 y = 16.$

Solve each of the following systems of equations by using the method of cross multiplication:

$3 x + 2 y + 25 = 0$ ,

$2 x + y + 10 = 0.$

0.3 x + 0.4 y = 2.5 and 0.5 x - 0.3 y = 0.3

2 x + 3 y = 17

3 x - 2 y = 6

Join BYJU'S Learning Program