If is the solution to the system of equations below, what is the value of ?
Answer: 2
Answer
The correct answer is 2.
Substituting into the second equation yields . Expanding this expression gives , which simplifies to . Subtracting 2 from both sides gives , and dividing by 7 yields .
Step-by-Step Solution
Key Concept
Solving a system of linear equations using the substitution method.
Alternative Method
Alternatively, you can multiply the first equation by 2 to get and subtract it from to eliminate , which also yields and thus .
Estimated Time:1m 0s