Question

Solve x+0.5y=3.5 and 0.5x-0.3y=1.9 by substitution method​

Answer 1

x+0.5y=3.5. .........................(1)

0.5x-0.3y=1.9. ......................(2)

from (1),x=3.5-0.5y. ................(3)

putting this value in (2)

0.5(3.5-0.5y)+0.3y= 1.9

1.75- 0.25y+0.3y=1.9

0.05y=0.15

y=0.15/0.05=3

now putting y=3 in eq(3)

x=3.5-(0.5×3)

x=2

hence x=2

and y= 3

it is the required solution

Answer 2

x+0.5y=3.5 ------1

0.5x-0.3y=1.9 (or) x+0.6y=3.8------2

substituting 1 and 2

x+0.6y-x-0.5y=3.8-3.5

0.1y=0.3

y=3

substituting y=3 in equation 1

x+1.5=3.5

x=2