Question

X-3y-7=6 and 3x-3y-15=0 cross multiplication

Answer 1

Answer

Given pair of linear equations

x – 3y – 7 = 0

3x – 3y – 15 = 0

⇒ x – y – 5 = 0 …(ii)

As we can see that a1 = 1, b1 = – 3 and c1 = – 7

and a2 = 1, b2 = – 1 and c2 = – 5

∴ Given pair of equations has unique solution

By cross - multiplication method, we have

On taking I and III ratio, we get

⇒ x = 4

On taking II and III ratio, we get

⇒ y = – 1

Answer 2

Answer:

x=1 and y = -4

Step-by-step explanation:

REMEMBER

    x          y          1

-3       -13       1           -3

-3       -15       3          -3

Hence,

______x_____   =      _____y______    =  _____1_____

(-3*-15) -  (-3*-13)              (-13*3) - (-15*1)          (1*-3) - (3*-3)

______x_____   =      _____y______    =  _____1_____

            6                                -24                            6          

x=1  and   y = -4

Hope it helps!