Elimination method in solving simultaneous equation, a+2b=13, 2a-3b=15

Answer 1

here
A+2B=13 2A-3B=5

Answer 2

if
a+2b=13
2a-3b=15
then multiply the first one by 2
2a+4b=26
2a-3b=15
-------------- subtract
0 + 7 b = 11
b = 11/7
now go back and get a
========================
if
A+2B=13
2A-3B=5
------------- multiply by 2 again
2A+4B=26
2A-3B=5
-----------------subtract again
7 b = 21
b = 3 much more reasonable
now go back and find a from either equation

Answer 3

clearly

Answer 4

OMG, ur soooo mean

Answer 5

I think we first eliminate the same coefficients and then change the signs