You add two equations together to eliminate a variable. This particular problem is nice, because it's already setup to eliminate X.
3x - 4y = 9
<span>-3x + 2y = 9
</span>
When we add these two together, 3x - 3x cancels each other out, leaving us with 0x, or nothing.
We continue with -4y + 2y (leaves us with -2y) and 9+9 (18).
-2y = 18
18/-2 = -9.
Now we have y = -9, and we can go back into the problems to solve for x.
<span>3x - 4(-9) = 9
</span>
3x + 36 = 9.
3x = -27
x = -9.
Confirm with the final equation:
-3(-9) + 2(-9) = 9
27 - 18 = 9
9 = 9 --- Confirmed.
Answer:
5.83
Step-by-step explanation:
Q1
Answer:

Step-by-step explanation:

explanation for second step:
you divide each side by 3 to get rid of the '3' in '3x'
Answer:
How many students like only tennis and football?
13 who like tennis and football
How many students like only baseball and football?
26 who like baseball and football
Answer:
10 %
Step-by-step explanation:
We first find change in the quantities
Then we write the change in quantity on original quantity and multiply by 100%
This implies that,



Therefore the percentage increase is 10%