Question

Solve the following systems of equations:
0.4x + 0.3y = 1.7
0.7x – 0.2y = 0.8

Answer 1

As/q

0.4x + 0.3y=1.7...(1)

0.7x - 0.2y= 0.8...(2)

multiplying eq 1 by 2 & eq 2 by 3, we get

0.8x + 0.6y = 3.4..(3)

2.1x - 0.6y = 2.4..(4) now adding eq 3&4

2.9x= 5.8

x=5.8/2.9

x=2

putting the value of x in eq (1)

0.4×2 + 0.3y=1.7

0.3y= 1.7-0.8

y=0.9/0.3

y=3

Answer x=2 y=3

Answer 2

$\Large{\textbf{\underline{\underline{According\;to\;the\;Question}}}}$

Given,

0.4x + 0.3y = 1.7………(1)

0.7x - 0.2y = 0.8………(2)

Now,

Multiply (1) by 20 and (2) by 30 we get,

8x + 6y = 34………..(3)

21x - 6y = 24………..(4)

Now,

Adding (3) and (4) we get,

29x = 58

x = 58/29

x = 2

Substituting value of x in (2),

0.7x - 0.2y = 0.8

0.7(2) - 0.2y = 0.8

1.4 - 0.2y = 0.8

-0.2y = 0.8 - 1.4

-0.2y = 0.6

y = 0.6/(-0.2)

y = -3

Therefore,

x = 2 and y = -3