# How do you solve y=4/x  and y=3x-1  using substitution?

Jul 1, 2016

$x = \frac{4}{3}$ or $x = - 1$

#### Explanation:

To solve $y = \frac{4}{x}$ and $y = 3 x - 1$ using substitution, just substitute value of $y$ from first equation into second, which leads to

$\frac{4}{x} = 3 x - 1$ or multiplying each by $x$ (we assome $x \ne 0$, we get

$4 = 3 {x}^{2} - x$ or

$3 {x}^{2} - x - 4 = 0$ or

$3 {x}^{2} + 3 x - 4 x - 4 = 0$ or

$3 x \left(x + 1\right) - 4 \left(x + 1\right) = 0$ or

$\left(3 x - 4\right) \left(x + 1\right) = 0$, which means that $3 x - 4 = 0$ or $x + 1 = 0$

i.e. $x = \frac{4}{3}$ or $x = - 1$