Question
Systems of Linear Equations Online Practice
Complete this assessment to review what you've learned. It will not count toward your grade.
7 of 137 of 13 Items
Question
Solve the system of equations.
x−3y=18
7x−5y=46
(1 point)
Responses
(105, 5)
left parenthesis 105 comma 5 right parenthesis
(33, 5)
left parenthesis 33 comma 5 right parenthesis
(3, −5)
left parenthesis 3 comma negative 5 right parenthesis
(−3, −5)
left parenthesis negative 3 comma negative 5 right parenthesis
Answers
GPT-4o mini
To solve the given system of equations:
1. \( x - 3y = 18 \) (Equation 1)
2. \( 7x - 5y = 46 \) (Equation 2)
Let's solve these equations step by step.
### Step 1: Solve for \( x \) in terms of \( y \) using Equation 1.
From Equation 1:
\[ x = 3y + 18 \]
### Step 2: Substitute \( x \) into Equation 2.
Substituting \( x \) in Equation 2 gives:
\[ 7(3y + 18) - 5y = 46 \]
### Step 3: Expand and simplify.
\[ 21y + 126 - 5y = 46 \]
Combine like terms:
\[ 16y + 126 = 46 \]
### Step 4: Solve for \( y \).
Subtract 126 from both sides:
\[ 16y = 46 - 126 \]
\[ 16y = -80 \]
\[ y = -5 \]
### Step 5: Substitute \( y \) back into Equation 1 to find \( x \).
Now substitute \( y = -5 \) back into the equation for \( x \):
\[ x = 3(-5) + 18 \]
\[ x = -15 + 18 \]
\[ x = 3 \]
### Final Solution
So, the solution of the system of equations is:
\[ (x, y) = (3, -5) \]
### Answer
The correct response is:
**(3, -5)**
1. \( x - 3y = 18 \) (Equation 1)
2. \( 7x - 5y = 46 \) (Equation 2)
Let's solve these equations step by step.
### Step 1: Solve for \( x \) in terms of \( y \) using Equation 1.
From Equation 1:
\[ x = 3y + 18 \]
### Step 2: Substitute \( x \) into Equation 2.
Substituting \( x \) in Equation 2 gives:
\[ 7(3y + 18) - 5y = 46 \]
### Step 3: Expand and simplify.
\[ 21y + 126 - 5y = 46 \]
Combine like terms:
\[ 16y + 126 = 46 \]
### Step 4: Solve for \( y \).
Subtract 126 from both sides:
\[ 16y = 46 - 126 \]
\[ 16y = -80 \]
\[ y = -5 \]
### Step 5: Substitute \( y \) back into Equation 1 to find \( x \).
Now substitute \( y = -5 \) back into the equation for \( x \):
\[ x = 3(-5) + 18 \]
\[ x = -15 + 18 \]
\[ x = 3 \]
### Final Solution
So, the solution of the system of equations is:
\[ (x, y) = (3, -5) \]
### Answer
The correct response is:
**(3, -5)**