(x² + 5x + 6)(x²-3x+4)=0 factoring

The length of a shadow of the building is 36m. the length of the pole, which is perpendicular to the ground, is 1.9m. the length of the pole's shadow is 1.52m. what is the height of the building?

Find the value of x for which line a is parallel to line b

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25