The given equations are
0.4x + 0.3y = 1.7 …(i)
0.7x – 0.2y = 0.8 …(ii)
Multiplying equation (i) by 2 and (ii) by 3 and then adding, we get
2.9x = 5.8
⇒ x = 2
Substituting the value of x in (i), we get
0.4 x 2 + 0.3y = 1.7
⇒ 0.3y = 1.7 – 0.8
⇒ 0.3y = 0.9
⇒ y = 3