Math, asked by Anonymous, 1 year ago

0 . 4 x - 1 . 5 y = 6.5

0.3x + 0.2y = 0.9

( Solve by substitution method )

Answers

Answered by VijayaLaxmiMehra1
44
\textbf{Solution:}

0.4 x- 1.5y = 6.5 - - (1)

0.3x + 0.2y = 0.9 - - (2)

From eq'n ( 1 )

0.4x - 1.5y = 6.5 \\ \\ = > 0.4x = 6.5 + 1.5y \\ \\ = > x = \frac{6.5 + 1.5y}{0.4} - - (3)

Substitute eq'n ( 3 ) in eq'n ( 2 )

0.3x + 0.2y = 0.9 \\ \\ = > 0.3( \frac{6.5 + 1.5y}{0.4} ) + 0.2y = 0.9 \\ \\ = > 1.95 + 0.45y + 0.08y = 0.36 \\ \\ = > 0.53y = 0.36 - 1.95 \\ \\ = > 0.53y = - 1.59 \\ \\ = > y = \frac{ - 1.59}{0.53} \\ \\ = > y = - 3

From eq'n ( 3 )

x = \frac{6.5 + 1.5y}{0.4} \\ \\ = > x = \frac{6.5 + 1.5( - 3)}{0.4} \\ \\ = > x = \frac{6.5 - 4.5}{0.4} \\ \\ = > x = \frac{2}{0.4} \\ \\ = > x = 5

\textbf{Therefore the value of}

\boxed{x = 5 , y = - 3}

\textbf{Hope it helps}

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Answered by TANU81
27
♥️Hi there ♥️

0.4 x - 1 . 5 y = 6.5 -----(1)

0.3x + 0.2y = 0.9---------(2)

from \: eq \: (1) \: x =  \frac{0.9 - 0.2y}{0.3}  -  - (3)

Now ,put it in eqn 1

0.4( \frac{0.9 - 0.2y}{0.3} ) - 1.5y = 6.5
0.36 - 0.08y - 0.45y = 1.95 \\  \\  - 0.08y - 0.45y =1.95 - 0.36 \\  \\  - 0.53y = 1.59 \\  \\ y =  \frac{1.59}{0.53}  \\  \\ y =  - 3
Now put y = -3 in equation (3)

 \frac{0.9 - 0.2( - 3)}{0.3}  =  \frac{0.9 + 0.6}{0.3}  = 5

Hence ,
x = 5 \\  \\ y =  - 3
Verification :-

0.4 (5) - 1.5(-3) = 6.5

2+ 4.5 = 6.

Verify ✔️

0.3(5)+0.2(-3) = 0.9

Same with this too.

Thanks !

Hope it will helpful.




VijayaLaxmiMehra1: :-)
TANU81: ^_^
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