Question

ayuda xfavor 2a+b=9 a-2b=8

Answer 1

(4a+2b=18 )    (2)
a-2b=8
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5a=26
a=26/5

2a+b=9
-2a+4b= -16   (2)
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5b=-7
b=-7/5

Answer 2

2a+b= 9   ...... I      por(2)
a-2b = 8  ....... II

4a +2b = 18
a  -  2b = 8
'''''''''''''''''''''''''''''
5a       =  26

a = 26/5   ....... III
 
III en I

2a + b = 9

$2 (\frac{26}{5} ) + b = 9$

$\frac{52}{5}+b = 9$

$b = 9- \frac{52}{5}$

$b = \frac{45-52}{5}$

$b = \frac{-7}{5}$

$CS=( \frac{26}{5} ; \frac{-7}{5} )$