1.	a.
		xy = 13x + 6 xy - 13x = 6 x(y - 13) = 6 x = 6/(y - 13)
	b.
		y(5x - 1) = 8 + 3x 5xy - y = 8 + 3x 5xy - 3x = 8 + y x(5y - 3) = 8 + y x = (8 + y)/(5y - 3)
	c.
		y(2x - 3) = 4x + 12(2x - 3) 2xy - 3y = 4x + 24x - 36 2xy - 28x = 3y - 36 x(2y - 28) = 3y - 36 x = (3y - 36)/(2y - 28)
	d.
		y(10 - 2x) = 12(10 - 2x) - 8 10y - 2xy = 120 - 24x - 8 24x - 2xy = 112 - 10y x(24 - 2y) = 112 - 10y x = (24 - 10y)/(112 - 2y) x = (12 - 5y)/(56 - y)
	e.
		y(5 - 3x) = 2x + 4 5y - 3yx = 2x + 4 -2x - 3yx = 4 - 5y x(2 + 3y) = 5y - 4 x = (5y - 4)/(3y + 2)
	f.
		2xy = 5 + 8x - 22 2xy - 8x = -17 x(2y - 8) = -17 x = -17/(2y - 8)
2.	a.	50 = (22p + 1500)/(4p + 6) 50(4p + 6) = 22p + 1500 200p + 300 = 22p + 1500 178p = 1200 p = 6,74
	b.	q = (22p + 1500)/(4p + 6)  q(4p + 6) = 22p + 1500 4pq + 6q = 22p + 1500 4pq - 22p = 1500 - 6q p(4q - 22) = 1500 - 6q p = (1500 - 6q)/(4q - 22)   q= 50  geeft  p = (1500 - 6 × 50)/(4 × 50 - 22) = 1200/178 = 6,74