# How do you solve 3a - b = 11 and 2a + 3b = 0 using substitution?

Mar 6, 2018

color(green)(a = 3, b = -2

#### Explanation:

$3 a - b = 11$ Eqn (1)

$b = 3 a - 11$

$2 a + 3 b = 0$ Eqn (2)

Substituting value of b in terms of a in Eqn (2),

$2 a + 9 a - 33 = 0$

$11 a = 33$ or color(green)(a = 3

Substituting value of a in Eqn (1),

$\left(3 \cdot 3\right) - b = 11$

$b = 9 - 11$, color(green)( b = - 2