Linear equations 3x + 5y = 19 and 10x - 3y = 24 have solution x = α/3 and y = β/2, then the value of α + β is:
(b) 13
We are given a system of two linear equations:
We need to find the values of \(x\) and \(y\) that satisfy both equations simultaneously. We can use the elimination method to solve this system.
To eliminate one of the variables, we can multiply the equations by suitable constants so that the coefficients of one variable become opposite in sign or equal. Let's aim to eliminate \(y\).
Now, we have the coefficient of \(y\) as \(+15\) in Equation 3 and \(-15\) in Equation 4. Adding these two equations will eliminate the \(y\) term.
Add Equation 3 and Equation 4:
\((9x + 15y) + (50x - 15y) = 57 + 120\)
\(9x + 50x + 15y - 15y = 177\)
\(59x = 177\)
Now, solve for \(x\):
\(x = \frac{177}{59}\)
\(x = 3\)
Substitute the value of \(x = 3\) into either of the original equations. Let's use Equation 1:
\(3x + 5y = 19\)
\(3(3) + 5y = 19\)
\(9 + 5y = 19\)
Subtract 9 from both sides:
\(5y = 19 - 9\)
\(5y = 10\)
Now, solve for \(y\):
\(y = \frac{10}{5}\)
\(y = 2\)
So, the solution to the system of linear equations is \(x = 3\) and \(y = 2\).
The problem states that the solution is \(x = \frac{\alpha}{3}\) and \(y = \frac{\beta}{2}\). We found \(x = 3\) and \(y = 2\).
So, we have \(\alpha = 9\) and \(\beta = 4\).
Finally, we need to find the value of \(\alpha + \beta\):
\(\alpha + \beta = 9 + 4 = 13\)
Therefore, the value of \(\alpha + \beta\) is 13.
| Step | Description | Application to this Problem |
|---|---|---|
| 1 | Set up the system of linear equations. | \(3x + 5y = 19\), \(10x - 3y = 24\) |
| 2 | Choose a method (Elimination/Substitution). | Elimination method chosen. |
| 3 | Modify equations to eliminate a variable. | Multiply Eq1 by 3, Eq2 by 5 to eliminate \(y\). Obtain \(9x + 15y = 57\), \(50x - 15y = 120\). |
| 4 | Add/Subtract modified equations. | Add modified equations: \(59x = 177\). |
| 5 | Solve for the first variable. | \(x = \frac{177}{59} = 3\). |
| 6 | Substitute the value back. | Substitute \(x = 3\) into \(3x + 5y = 19\). |
| 7 | Solve for the second variable. | \(9 + 5y = 19 \implies 5y = 10 \implies y = 2\). |
| 8 | Compare solution with given form. | \(x = 3 = \frac{\alpha}{3}\), \(y = 2 = \frac{\beta}{2}\). |
| 9 | Solve for α and β. | \(\alpha = 9\), \(\beta = 4\). |
| 10 | Calculate the required value. | \(\alpha + \beta = 9 + 4 = 13\). |
A system of linear equations is a set of two or more linear equations involving the same variables. The solution to a system of linear equations in two variables (\(x\) and \(y\)) is a pair of values \((x, y)\) that satisfies every equation in the system.
There are several methods to solve a system of linear equations:
The number of solutions a system of two linear equations in two variables can have is:
In this specific problem, we found exactly one solution (\(x=3, y=2\)), which is typical for many linear systems encountered in algebra.
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