Differentiated simultaneous equations treasure hunts (10 cards for each difficulty)

A set of differentiated treasure hunts. Answers included.

Please see here for a FREE version of the Blue treasure hunt.

The 3 levels of difficulty are:
• Blue (easy) - solve simultaneous equations where the coefficient of x OR y is 1. E.g.
10x + y = 4
8x + y = 25
•Gold (medium) - solve simultaneous equations where the coefficient of x OR y is a factor of the other x or y E.g.
4y + 7x = 117
2y + 2x = 40
•Red (harder) - solve simultaneous equations where x and y are random integers or decimals E.g.
4y - 3x = 34.5
6y + 5x = 56.5