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42 votes
42 votes
4х + 5y = 19 8х - бу = -10

User Siliconrockstar
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1 Answer

13 votes
13 votes

\text{x = 1, y = 3}

Here, we want to solve the system of linear equations simultaneously

We start by multiplying the first equation by 2 and the second by 1


\begin{gathered} 8x\text{ + 10y = 38} \\ 8x-6y\text{ = -10} \end{gathered}

We can now proceed to subtract the second equation from the first

That will give;


\begin{gathered} (8x-8x)+(10y-(-6y))\text{ = 38-(-10)} \\ 16y\text{ = 48} \\ y\text{ = }(48)/(16) \\ y\text{ = 3} \end{gathered}

To get the value of x, we will need to substitute the calculated value of y into any of the two initial equations

Thus, we have it that;


\begin{gathered} 4x\text{ + 5(3) = 19} \\ 4x\text{ + 15 = 19} \\ 4x\text{ = 19-15} \\ 4x\text{ = 4} \\ \text{ x = }(4)/(4) \\ x\text{ = 1} \end{gathered}

User Srikan
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