Answer:
Explanation:
If a + 3b = 7, subtract 3b from both sides of the equation
-3b = -3b then you get
a = 7-3b now plug this into the other equation: 3a-2b=8
3(7-3b) - 2b = 8
21 - 9b - 2b = 8
21 - 11b = 8 add 11 b to both sides
+ 11b +11b
21 = 8 + 11b subtract 8 from both sides
-8 -8
13 = 11b
What is 4a+b?
4(7-3b) + b =
(28 - 12b) + b =
28-11b (from above 13=11b)
28 - 13 = 15