Question

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

Answer 1

Equations can be rewritten as :

$\Rightarrow 4x+3y=17$

$\Rightarrow 7x-2y=8$

Multiply 1st equation by 2 and 2nd equation by 3

$\Rightarrow 8x+6y=34$

$\Rightarrow 21x-6y=24$

Add two equations ;

$\Rightarrow 29x=58$

$\Rightarrow x=2$

Substitute x in equation (1);

$\Rightarrow 3y=9$

$\Rightarrow y=3$

$\therefore x=2,y=3$