Sum of 5 times z and 4 divided by two is 7.
1.(-3/2,3)
2.(5/2,2)
3.(5,4)
4.(7/2,-1)
5.(9/2,-1)
I gave the midpoints what do you mean by the given endpoints
The smallest one is -2/7
The largest one is 8/9 The difference between them is
8/9 - - 2/7 =
8/9 + 2/7 =
7*8/9*7 + 2*9/9*7 =
56 / 63 + 18 / 63 =
74 / 63 =
1 11/63
1/3 (8-x)
Hope that helps, good luck