Question

Solve the following pair of equations using cross-multiplication method:
x-3y – 7=0
3x - 5y - 15 = 0​

Answer 1

Step-by-step explanation:

$x = - 29 \\ y = - 12$

Answer 2

Answer: The following pair of equations using cross multiplication are solved as follows:

- Cross multiplication method

step-wise process.

- step 1 : we have to find solution for equations:

(i) x - 3y - 7 = 0

(ii) 3x - 5y - 15 = 0

- step 2 : Multiply equation (i) by - 5 and equation (ii) by -3 to get

-5x + 15y + 35 = 0 ....(iii)

-9x + 15y + 45 = 0 ....(iv)

- step 3 : subtracting equation (iv) from (iii) , we get

( -5 + 9 )x + (15 - 15)y + (35 - 45)

= 4x + 0y - 10 = 0

= 4x = 10

so, x = 10/4 = 5/2

- Step 4 : By putting the value of x in equation (i) we get value of y i.e.

(5/2) - 3y - 7 =0

- 3y = 7 - 5/2

- 3y = 14 - 5/2

-3y = 9/2

y= - 9/6

y= - 3/2

So value of x=5/2 and value of

y = -3/2