If 2x - 3y = -11 and 3x + 2y = 3, evaluate \( (y - x)^2\)

a. In a football match, tickets for children and adults were sold at D3.00 and D5.00 respectively. if 400 people attended a football match and D1700.00 was collected in ticket sales. How many tickets were sold to adults?

b. Mr Johnson sold 250 tickets. If 175 of the tickets were for adults, how much sales did he make altogether?

a. The sum of three numbers is 81. The second number is twice the first. given that the third number is 6 more than the second, find the numbers.

b. Give me the points P(3, 5) and Q(-5, 7) on the Cartesian plane such that R (x, y) is the midpoint of PQ, find the equation of the line that passes through R and perpendicular to line PQ.