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Matrics — Maths STD 12 Science — Question

Maharashtra BoardEnglish MediumSTD 12 ScienceMathsMatrics3 Marks
Question
Solve the following equations by reduction method : 5x + 2y = 4, 7x + 3y = 5
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Answer

5x + 2y = 4 ………..(1)
7x + 3y = 5 …………(2)
Multiplying Eq. (1) with 7 and Eq. (2) with 5

\begin{array}{c}
35 x+14 y=28 \\
35 x+15 y=25 \\
-\quad- \\
\hline-1 y=3 \\
y=-3
\end{array}

Put y = -3 into Eq. (1)
5x + 2y = 4
5x + 2(-3) = 4
5x – 6 = 4
5x = 4 + 6
5x = 10
$x=\frac{10}{5}$
x = 2
Hence, x = 2, y = -3 is the required solution.

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