Multiply both sides of first equation by 2
2 a + 4 b = 26
Subtract the second equation from the first
2 a + 4 b = 26
-
2 a - 3 b = 5
___________
2 a - 2a + 4 b - ( - 3 b ) = 26 - 5
4 b + 3 b = 21
7 b = 21
b = 21 / 7
b = 3
Replace b by 3 in first equation
a + 2 b = 13
a + 2 ∙ 3 = 13
a + 6 = 13
a = 13 - 6
a = 7
The solution is:
a = 7 , b = 3
a+2b=13
2a-3b=5
1 answer