A class sets up 40 chairs. There 8 chairs in each row. How many rows of chairs are there?
1 answer:
You might be interested in
Answer:
- a = $8
- s = $5
Step-by-step explanation:
When the coefficients don't lend themselves to solution by substitution or elimination, then Cramer's Rule can be useful. It tells you the solutions to
- ax +by = c
- dx +ey = f
are ...
- ∆ = bd -ea
- x = (bf -ec)/∆
- y = (cd -fa)/∆
Using that rule here, we find ...
∆ = 5·3 -6·2 = 3
a = (5·54 -6·41)/3 = 5·18 -2·41 = 90 -82 = 8
s = (41·3 -54·2)/3 = 41 -18·2 = 5
This math can be performed in your head, which is the intent of formulating the rule in this way.
_____
Similarly, if you expect the solutions to be small integers (as here), then graphing is another viable solution method.
_____
<em>Comment on the question</em>
We're sad to see than only 16 tickets were sold to the two performances by the symphonic band.
