The point (-4,8) is the mid point of the line joining the points (a+b,3b) and (-2a,2b-3a) find the values of a and b

a=28; b=20.

Step-by-step explanation:

1) 2*(-4)=(a+b)+(-2a) and .

2) using the two equations it is possible to make up (then solve) the next system:

x = -4

step-by-step explanation:

- 20 - 4(x + 3) = 4x

=> -20 - 4x - 12 = 4x

=> - 32 -4x = 4x

=> -32 = 4x + 4x

=> - 32 = 8x

=> -32/8 = x

=> -4 = x