A system of two linear equations is given below.
If is the solution to the system of equations, what is the value of ?
- 5Answer
- B-7
- C-5
- D7
Answer
The value of is 5.
To find the value of , substitute the expression for from the first equation into the second equation: . Distribute the to obtain , which simplifies to . Subtracting 6 from both sides gives . Multiplying or dividing both sides by yields .
Step-by-Step Solution
Key Concept
Solving systems of linear equations using the substitution method
Alternative Method
Alternatively, you can solve this system using elimination. First, rewrite the first equation in standard form by subtracting from both sides, which gives . Next, multiply this equation by 3 to align coefficients: . Adding this result directly to the second equation, , eliminates the terms and leaves , which simplifies to .
Estimated Time:45s