Question

If 3a-2b=8 and a+3b=7 what is the value of 4a+b

Answer 1

Answer:

Step-by-step 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