Question

3a+9b=8b-a 5a-10b=4a-9b+5
What does a and b equal?

Answer 1

3 a + 9 b = 8 b - a
and
5 a - 10 b = 4 a - 9 b + 5 ?????
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simplify row 1
4 a + 1 b = 0
simplify row two
1 a - 1 b = 5
----------------- add the two rows to get rid of b
5 a = 5
so
a = 1
go back and get b
b = -4

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check

Answer 2

3a+9b=8b-a
5a-10b=4a-9b+5
get them in standard order first///

Na+Mb=k
see if that helps

Answer 3

Are you to solve these equations simultaneously? Does the first equation have a constant or is 3a+9b = 8b-a it?
First combine the terms; for example, the first equation would b ecome
3a + 9b = 8b - a
3a + a + 9b -8b
4a+b = 0
Treat equation 2 the same, the solve by substitution or elimination.