#### Answer

$x_{1}$= 3 ; $x_{2}$=-2

#### Work Step by Step

(1) 0.05$x_{1}$ - 0.03$x_{2}$ = 0.21
(2) 0.07$x_{1}$ + 0.02$x_{2}$ = 0.17
100$R_{1}$→$R_{1}$
100$R_{2}$→$R_{2}$
(3) 5$x_{1}$ - 3$x_{2}$ = 21
(4) 7$x_{1}$ + 2$x_{2}$ = 17
2$R_{1}$→$R_{1}$
3$R_{2}$→$R_{2}$
(5) 10$x_{1}$ - 6$x_{2}$ = 42
(6) 21$x_{1}$ + 6$x_{2}$ = 51
$R_{1}$+$R_{2}$→$R_{2}$
31$x_{1}$ = 93
$x_{1}$ = 3, plug this value into (5)
10(3) - 6$x_{2}$ = 42
30 - 6$x_{2}$ = 42
-6$x_{2}$ = 12
$x_{2}$ = -2