10≤n<100
So the number of two digit numbers is 99-10+1=90
The only combinations that sum to 5 are 14, 23, 32, 41, 50 so
P(sum=5)=5/90
P(sum=5)=1/18
Solve by substitution


Just plug in y=-x-1 into y+x=3
So we get:

Simplify that:

And since that is not true, that means this system of equations has no solutions!
21. Broooooo, This is baby stuff!
Answer:
79%
Step-by-step explanation:
To find the median, you need to arrange the numbers in ascending order. Than pick the middle number. If there are two middle numbers then you add them together and then divide by 2.