# How do you solve the system using the elimination method for 3a + 5b – 7 = 0 and a – 2b – 4 = 0?

Apr 8, 2018

$a = \frac{34}{11} \mathmr{and} b = - \frac{5}{11}$

#### Explanation:

Let $3 a + 5 b - 7 = 0$ be equation (1); and $a - 2 b - 4 = 0$ be equation (2).

Multiplying (2) by 3 gives: $3 a - 6 b - 12 = 0$ (Let’s call this (2A))

Eliminate $b$’s by subtracting (2A) from (1) gives: $11 b + 5 = 0 \to b = - \frac{5}{11}$

Substituting $b = \frac{5}{11}$ into (2) gives $a - 2 \left(- \frac{5}{11}\right) - 4 = 0 \to a = \frac{34}{11}$