Question

x+y =3 and 2x+5y=12 by cros's multiplication method​

Answer 1

Step-by-step explanation:

x+y/2x+5y =3/12=1/4

where X+y=8X+20y

or

substitute X and y values

Answer 2

a1 = 1, a2 = 2, b1 = 1, b2 = 5, c1=-3, c2 -12

x = b1c2-b2c1/ a1b2-a2b1

= (1)(-12) - (5)(-3)/(1)(5)-(2)(1)

= -12+15/3 = 3/3 = 1

y = c1a2-c2a1/a1b2-a2b1

= (-3)(2)-(-12)(1)/3

= -6+12/3 = 6/3 = 2

hence, x= 1 & y=2