sandy wrote:
\(2x + 3y = 29\)
\(3x + 4y = 41\)
Quantity A: \(x +y\)
Quantity B: 12
Nice question.
This one is a classic, because many students feel they need to solve the linear system for x and for y.
HOWEVER, the question doesn't require us to find the individual values of x and y.
All we need to do is find the value of x + y (quantity A)
We have
2x + 3y = 29 AND
3x + 4y = 41Subtract the first equation from the second question to get:
(
3x + 4y) - (
2x + 3y) =
41 -
29Simplify to get x + y = 12
Answer:
Cheers,
Brent
_________________
Brent Hanneson - founder of Greenlight Test Prep