The solution of the two simultaneous equations 2x + y = 8 and 3y = 4 +

1.	The solution of the two simultaneous equations 2x + y = 8 and 3y = 4 + 4x is : (a) x = 4, y = 1 (b) x = 1, y = 4 (c) x = 2, y = 4 (d) x = 3, y = –4
Answer» (c) x = 2, y = 4 2x + y = 8 ............…(i) – 4x + 3y = 4 ..............(ii) Multiplying eqn (i) by 2 and adding to eqn (ii), we get 4x + 2y – 4x + 3y = 16 + 4 \(\Rightarrow\) 5y = 20 \(\Rightarrow\) y = 4 Putting y = 4 in (i), we get 2x + 4 = 8 \(\Rightarrow\) 2x = 4 \(\Rightarrow\) x = 2.

The solution of the two simultaneous equations 2x + y = 8 and 3y = 4 + 4x is : (a) x = 4, y = 1 (b) x = 1, y = 4 (c) x = 2, y = 4 (d) x = 3, y = –4

Answer»

(c) x = 2, y = 4

2x + y = 8 ............…(i)

– 4x + 3y = 4 ..............(ii)

Multiplying eqn (i) by 2 and adding to eqn (ii), we get

4x + 2y – 4x + 3y = 16 + 4

\(\Rightarrow\) 5y = 20

\(\Rightarrow\) y = 4

Putting y = 4 in (i), we get 2x + 4 = 8

\(\Rightarrow\) 2x = 4

\(\Rightarrow\) x = 2.