Question

solve by only cross multiplication method :- 5x-6y+30=0, 5x+4y-20=0​

Answer 1

5x-6y+30=0,

5x+4y-20=0

Cross Multiplication Method-

b1 c1 a1 b1

X X X

b2 c2 a2 b2

-6 30 5 -6

X X X

4 -20 5 4

X/(b1c2 - b2c1) = Y/(c1a2 - c2a1) = 1/(a1b2 - a2b1)

=> X/(120 - 120) = Y/(150 - 100) = 1/(20 + 30)

=> X/0 = Y/50 = 1/50

so,

X = 0

& Y = 50/50 = 1. (ans.)