How do you solve a-3b=2  and 2a+4b=9?

Jul 2, 2018

color(green)(a = 7/2, b = 1/2

Explanation:

$a - 3 b = 2 , \text{ Eqn (1)}$

$2 a + 4 b = 9 , \text{ Eqn (2)}$

$\text{Eqn (2) "- 2 * " Eqn (1) is }$

$\cancel{2 a} + 4 b - \cancel{2 a} + 6 b = 9 - 4$

$10 b = 5 \text{ or } b = \frac{1}{2}$

$a - \left(3 \cdot \left(\frac{1}{2}\right)\right) = 2$

$a = 2 + \frac{3}{2} = \frac{7}{2}$