What is the solution to the system of equations below?
x + 3 y = 15 and 4 x + 2 y = 30
(6, 3)
(3, 6)
(7, –6)
(–6, 7)
The Correct Answer and Explanation is :
The correct answer is: (6, 3).
To solve the system of equations given by:
- ( x + 3y = 15 ) (Equation 1)
- ( 4x + 2y = 30 ) (Equation 2)
we can use the substitution or elimination method. Here, I’ll demonstrate the elimination method.
First, we can manipulate Equation 1 to express one variable in terms of the other. Let’s solve for ( x ) in terms of ( y ):
[
x = 15 – 3y \tag{Equation 3}
]
Next, we can substitute Equation 3 into Equation 2:
[
4(15 – 3y) + 2y = 30
]
Now, distribute ( 4 ):
[
60 – 12y + 2y = 30
]
Combine like terms:
[
60 – 10y = 30
]
Now, isolate ( y ) by subtracting ( 60 ) from both sides:
[
-10y = 30 – 60
]
[
-10y = -30
]
Now, divide both sides by ( -10 ):
[
y = 3
]
Next, substitute ( y = 3 ) back into Equation 3 to find ( x ):
[
x = 15 – 3(3)
]
[
x = 15 – 9
]
[
x = 6
]
Thus, the solution to the system of equations is ( (6, 3) ).
To verify, we can substitute ( x = 6 ) and ( y = 3 ) back into both original equations:
- For Equation 1:
[
6 + 3(3) = 6 + 9 = 15 \quad \text{(True)}
] - For Equation 2:
[
4(6) + 2(3) = 24 + 6 = 30 \quad \text{(True)}
]
Since both equations are satisfied, the solution ( (6, 3) ) is correct. Thus, the answer to the system of equations is (6, 3).