To solve problems like this you can either graph or solve mathematically. To do the ladder we need to solve for one variable at a time. So lets cancel one variable out.
Multiply equation 1 by 2
This will give 4x-2y=14
Now we can get rid of y by subtracting 2 from 1
This will give x=9
Plug back in to either equation, i will use equation 2
3(9)-2y=5 simplify
-2y=-22 solve
Y=11
Answer:

Step-by-step explanation:
Possibilities (G for girls and B for boys):
GGG
GGB
GBG
<u>GBB
</u>
BGG
<u>BGB
</u>
<u>BBG
</u>
BBB
I am attaching an image with the two solutions represented by the blue areas highlighted in your original graphs. Let me know if you have questions.
Answer:
140
-2.6
0
Step-by-step explanation:
60 -(-80) if there is - - that means +
60 + 80 = 140
2.3 + (-4.9) if its + - it just means - ignore the plus
2.3 - 4.9
-2.6
4.5 + (-4.5)
0