Hello here is a solution :
<span> midpoint between A and B,is :C( (Xa+xb)/2; (ya+yb)/2)
C( (-1-3)/2;(5-7)/2)
C(-2 ; -1)</span>
Answer:
6x-21+5 = -19 Distribute
6x-16 = -19 Combine like terms
6x = -3 Add
x = -1/2 Division
Ratio 10:6
so 10+6 = 16
112/16 =7
white balls: 10 * 7 = 70
striped balls: 6 * 7 = 42
Answer: he needs to add 70 white balls and 42 striped balls to keep the same ratio 10:6