How do you solve y = 2x – 4 and 7x – 5y = 14 using substitution?

Jul 31, 2016

x=2; y=0

Explanation:

Since $y = 2 x - 4$, let's substitute the expression $2 x - 4$ in y in the second equation:

$7 x - 5 \left(2 x - 4\right) = 14$

$7 x - 10 x + 20 = 14$

$- 3 x = 14 - 20$

$- 3 x = - 6$

$x = 2$

Now let's substitute the value 2 in x in the first equation:

$y = 2 \left(2\right) - 4 = 0$