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3 years ago

Solve the equation -7 (8a - 9 = - 23 + 4a

Mathematics

1 answer:

Vikentia [17]3 years ago

3 0

Answer:

a = 43 / 30

Step-by-step explanation:

-7 ( 8a -9 ) = -23 + 4a

-56a + 63 = -23 +4a

-60a + 63 = -23

-60a = -86

a = 43 / 30

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17) Solve the system as matrix equations using inverses. 17) A company produces three models of MP3 players, models A, B, and C.

Vinvika [58]

Answer:

Model A=30, Model B: 20, Model C: 45

Step-by-step explanation:

Let x be the amount of type A mp3 produced, and the amount of model B mp3's produced and z the amount of model C mp3 produced.

Since in total there are 303 hours for electronics work, then:

$3.2x+5.4y+2.2z=303$

Since in total there are 393 hours for assembly, then:

$2.8x+2.4y+5.8z=393$

Since in total there are 416 hours for quality assurance, then:

$4.4x+3.4y+4.8z=416$

Then, the linear system associated to the problem is

$3.2x+5.4y+2.2z=303\\2.8x+2.4y+5.8z=393\\4.4x+3.4y+4.8z=416$

with coefficient matrix $A=\left[\begin{array}{ccc}3.2&5.4&2.2\\2.8&2.4&5.8\\4.4&3.4&4.8\end{array}\right]$ and vector of constant terms $b=\left[\begin{array}{ccc}303\\393\\416\end{array}\right]$

Since the determinant of A is equal to 36.704 then A is invertible.

Then for solve the system $Ax=b$ , is enough find the inverse of A and operate

$Ax=b\\A^{-1}Ax=A^{-1}b\\x=A^{-1}b$

Using Octave we obtain that

$A^{-1}=\left[\begin{array}{ccc}-0.22&-0.50 &0.71\\0.33&0.15&-0.34\\-0.028& 0.35&-0.20\end{array}\right]$

Then

$x=A^{-1}b=\left[\begin{array}{ccc}30\\20\\45\end{array}\right]$

This means that 30 mp3's of model A, 20 of model B and 45 of model C must be produced

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3 years ago

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Elden [556K]

Answer:

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Step-by-step explanation:

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3 years ago

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kirza4 [7]

Answer:

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Step-by-step explanation:

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$d = \sqrt{ {(x - 0)}^{2} + {(y - 0)}^{2} } \\ \\ \red{ \bold{ d = \sqrt{ {x}^{2} + {y}^{2} } }}$

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2 years ago

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Naya [18.7K]

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3 years ago

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statuscvo [17]

12/4(-1)+2=

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2 years ago

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