A: 5x − 2y = 10

Mathematics

1 answer:

Nuetrik [128]3 years ago

7 0

Answer:

D) Multiply A by -4 and B by 5

Step-by-step explanation:

5x-2y=10

4x+3y=7

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-4(5x-2y)=-4(10)

5(4x+3y)=5(7)

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-20x+8y=-40

20x+15y=35

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23y=-5

y=-5/23

5x-2(-5/23)=10

5x+10/23=10

5x=10-10/23

5x=230/23-10/23

5x=220/23

x=(220/23)/5

x=(220/23)(1/5)

x=220/115

x=44/23

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Answer:

Step-by-step explanation:

The model fo the shell is given by the following equation of equilibrium:

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$\int\limits^t_{0\,s} \, dt = -\frac{m}{b} \int\limits^{0\,\frac{m}{s} }_{600\,\frac{m}{s} } {\frac{1}{ v^{2}+\frac{m}{b}\cdot g } } \, dv$

The solution of this integral is:

$t = -\frac{m}{2b}\cdot \left[\tan^{-1} \left(\frac{v}{\sqrt{\frac{m\cdot g}{b} } }\right) - \tan^{-1} \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } }\right)\right]$

$\tan^{-1} \left(\frac{v}{\sqrt{\frac{m\cdot g}{b} } } \right)=-\frac{2\cdot b\cdot t}{m} + \tan^{-1}\left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)$

$\frac{v}{\sqrt{\frac{m\cdot g}{b} } }=\tan \left[-\frac{2\cdot b\cdot t}{m} + \tan^{-1}\left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)\right]$

$v = \sqrt{\frac{m\cdot g}{b} } \left [\frac{\tan \left(-\frac{2\cdot b \cdot t}{m} \right)+ \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)}{1 - \left(\frac{600}{\sqrt{\frac{m\cdot g}{b} } } \right)\cdot \tan \left(-\frac{2\cdot b \cdot t}{m} \right) }\right]$