Answer:
I need the values of either X or Y to solve this. I can solve for what X is though.
Step-by-step explanation:
A: X = -12
B: X =78
C: X = 12.13
I hope this helps you, but since both X and Y are unknown variables, you can't solve it, only simplify (which it already is.)
Answer:
There are a total of possible 1820 results.
Step-by-step explanation:
Since there are two competitions, one for boys and one for girls, and we want all the possible results we will calculate the possible combinations for the boys and multiply them by the possible combinations for the girls. This is shown below:
![Boys = \frac{15!}{3!(15 - 3)!} = \frac{15!}{3!12!} = \frac{15*14*13*12!}{3!12!}\\Boys = \frac{15*14*13}{3*2*1}\\Boys = \frac{15*14*13}{3*2*1}\\Boys = 455](https://tex.z-dn.net/?f=Boys%20%3D%20%5Cfrac%7B15%21%7D%7B3%21%2815%20-%203%29%21%7D%20%3D%20%5Cfrac%7B15%21%7D%7B3%2112%21%7D%20%3D%20%5Cfrac%7B15%2A14%2A13%2A12%21%7D%7B3%2112%21%7D%5C%5CBoys%20%3D%20%5Cfrac%7B15%2A14%2A13%7D%7B3%2A2%2A1%7D%5C%5CBoys%20%3D%20%5Cfrac%7B15%2A14%2A13%7D%7B3%2A2%2A1%7D%5C%5CBoys%20%3D%20455)
![Girls = \frac{4!}{3!*(4 - 3)!}\\Girls = \frac{4*3!}{3!}\\Girls = 4](https://tex.z-dn.net/?f=Girls%20%3D%20%5Cfrac%7B4%21%7D%7B3%21%2A%284%20-%203%29%21%7D%5C%5CGirls%20%3D%20%5Cfrac%7B4%2A3%21%7D%7B3%21%7D%5C%5CGirls%20%3D%204)
Total number of possible results:
![results = 4*455\\results = 1820](https://tex.z-dn.net/?f=results%20%3D%204%2A455%5C%5Cresults%20%3D%201820)
3a+11=7a-13
move 7a to the other side
sign changes from +7a to -7a
3a-7a+11= 7a-7a-13( combine like terms)
3a-7a+11= -13
-4a+11= -13
move 11 to the other side
sign changes from +11 to -11
-4a+11-11= -13-11
-4a= -13-11
-4a= -24
divide both sides by -4 to get a by itself
-4a/-4= -24/-4
Answer: a= 6