Easy
Medium
Hard
100

(x + 4) (x + 2)

x2 + 6x + 8

100

(x +6) (x - 4)

x2 + 2x -24

100

- (x +4) (x+2)

- x2 -6x -8

200

(x + 9) (x +8)

x2 + 17x + 72

200

(x -2) (x+7)

x2 +5x - 14

200

- (3x -8) (2x -9)

-6x2 +43x +72

300

(x + 12) (x + 14)

x2 - 26x + 168

300

(2x + 3) (3x -7)

6x2 - 5x -21

300

-2 (2x -3) (x +4)

-4x2 -10x +24

400

(7 + x) (x + 8)

x2 + 15x + 56

400

(5x +3) (2x -8)

10x2 -34x  - 24

400

(x -4) (-2) (2x+3)

-4x2 -10x +24

500

(15 + x) (x +14) 

x2 + 29x + 210

500

(4x - 5) (6x - 7)

24x2 -58x + 35

500

-3 (x -4) (x-3)

-3x2 +21x -36