bearing in mind that
standard form for a linear equation means
• all coefficients must be integers, no fractions
• only the constant on the right-hand-side
• all variables on the left-hand-side, sorted
• "x" must not have a negative coefficient
8 - 5y = - 2x
2x - 5y = - 8
You can make 6 different towers. If red was at the bottom, there'd be two different possibilities for that: red, yellow, blue, and red, blue, yellow. Same for if blue was at the bottom: blue, red, yellow, and blue, yellow, red. Yellow also applies: yellow, red, blue, and yellow, blue, red. 3*2=6, so 6 possible towers.
The javelin will hit the ground 14.66 or 15 seconds upon Maria's release from the said distance. The computation are as follows:
time = distance/speed (d/m)
time = 22 meters/second / 1.5 meters
time = 14.66 seconds or 15 seconds
I would say that the last one would be the most accurate.