Answer:
2(x/y)+40
Step-by-step explanation:
2(x/y)+40
<span>commutative property of multiplication</span>
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Answer:
ni nin i ni ni ni
Step-by-step explanation:
ni ni ni ni ni ni ni ni
We can find the answer by solving the two equations simultaneously.
equation 1: y = -0.4x^2 +3xequation 2: x + y = 10
We need to write equation to with y as the subject:equation 2: y = 10 - x
equation 1 = equation 2:
10 - x = -0.4x^2 + 3x0.4x^2 - 4x + 10 = 02x^2 - 20 + 50 = 0(2x - 10)(x - 5) = 0x = -10/2 or x = 5
<span>But x >= 0 (the question says it's a height </span>above<span> the water), so x = 5</span>
Substituting x = 5 into one of the equations:
y = 10 - x
y = 10 - 5
y = 5
<span>So the answer is C</span>