# How do you solve 0.1x + 0.6y = -1 and 0.2x - 0.7y = 3.7 using substitution?

Jul 25, 2016

$x = - 3$
$y = - \frac{7}{6}$

#### Explanation:

$0.1 x + 0.6 y = - 1$
Multiplying both sides by 10 we get
$x + 6 y = - 10$
Similarly multiplying both sides of $0.2 x - 0.7 y = 3.7$by 10
we get
$2 x - 7 y = 37$
Similarly multiplying both sides of $x + 6 y = - 10$ by $2$
we get
$2 x + 12 y = - 20$
Subtracting $2 x - 7 y = 37$ from $2 x + 12 y = - 20$
we get
$2 x + 12 y - 2 x + 7 y = - 20 - 37$
or
$19 x = - 57$
or
$x = - \frac{57}{19}$
or
$x = - 3$------------Ans$1$

Since from above we have Equation $x + 6 y = - 10$
By putting value of x=-3 in the above equation we get
$- 3 + 6 y = - 10$
or
$6 y = - 7$
or
$y = - \frac{7}{6}$------------Ans$2$