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

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Answer 1 · 2018-07-02T09:08:54

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

$a - 3b = 2, " Eqn (1)"$

$2a + 4b = 9, " Eqn (2)"$

$"Eqn (2) "- 2 * " Eqn (1) is "$

$cancel(2a) + 4b - cancel(2a) + 6b = 9 - 4$

$10 b = 5 " or " b = 1/2$

$a - (3 * (1/2)) = 2$

$a = 2 + 3/2 = 7/2$

How do you solve a-3b=2 a-3b=2 and 2a+4b=92a+4b=9?