How do you solve $3 a + 13 = 9 a - 8$ $3a+13=9a-8$ ?

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Answer 1 · 2016-12-21T04:40:53

$a = \frac{7}{2}$ $a = 7/2$

First, isolate the $a$ $a$ terms on one side of the equation and the constants on the other side of the equation while keeping the equation balanced:

$3 a + 13 - 3 a + 8 = 9 a - 8 - 3 a + 8$ $3a + 13 - color(red)(3a + 8) = 9a - 8 - color(red)(3a + 8)$

$3 a - 3 a + 13 + 8 = 9 a - 3 a - 8 + 8$ $3a - 3a + 13 + 8 = 9a - 3a - 8 + 8$

$0 + 13 + 8 = 9 a - 3 a - 0$ $0 + 13 + 8 = 9a - 3a - 0$

$13 + 8 = 9 a - 3 a$ $13 + 8 = 9a - 3a$

Next, we can combine like terms:

$21 = (9 - 3) a$ $21 = (9 - 3)a$

$21 = 6 a$ $21 = 6a$

Now, solve for $a$ $a$ while keeping the equation balanced:

$\frac{21}{6} = \frac{6 a}{6}$ $21/color(red)(6) = (6a)/color(red)(6)$

$(3 xx 7)/(3 xx 2) = (color(red)(cancel(color(black)(6)))a)/color(red)(cancel(color(black)(6)))$

$3/3 xx 7/2 = a$

$1 xx 7/2 = a$

$7/2 = a$

How do you solve 3a+13=9a-83a+13=9a−83a+13=9a-8?