X + y = 1.....multiply by -2
2x - 3y = -30
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-2x - 2y = -2 (result of multiplying by -2)
2x - 3y = -30
----------------add
-5y = -32
y = -32/-5
y = 32/5 or 6.4 <===
What does that even mean? can you re-word the question please?
One metre=10 decimetres.
Therefore 30 metres = 30*10=300 decimetres.
SOLUTION
The object would hit the ground at the root of the equation, that is where h = 0
So we have

Solving the quadratic equation, we have

So we ignore -1 as time cannot be negative.
Hence the object hit the ground in 3 seconds