First you can solve for b: Subtract a on both sides and get 2b=-a+10, then divide by 2 to get b by itself and get: b=-1/2a+5
Then you can plug in this equation for b in the other: This would give you: 2a+-1/2a+5=6. Then you can use that equation to solve for a and get: 1.5a+5=6, subtract 5, 1.5a=1, divide by 1.5, a=1/1.5
Then you can plug in the value of a to solve for b.
Answer: The greatest common factor is 2.
Step-by-step explanation: We are given to find the greatest common factor of the following expressions:

<u>Greatest Common Factor:</u> The GCF of two or more numbers (expressions) is the greatest factor that divides all the numbers or expressions.
We have

Therefore, the greatest common factor will be

Thus, the required greatest common factor is 2.
<span>Each team in the softball league plays each of the other teams exactly once. For every game, there is 2 team playing. The order is not important because A vs B is same as B vs A
So you just need to makes a combination of 2 that have a result of 21. If there is t number of teams, the number of matches would be:
tC2 = t!/2!(t-2)! = 21
</span>t! / (t-2)! = 21 *2
(t)(t-1)= 42
t^2 -t -42=0
(t-7)(t+6)
t=7 ; t=-6
Excluding the minus result, you got 7 teams.
A-2b=-10
add 2b on both sides
a=2b-10
add 10 to both sides
a+10=2b
divide both sides by 2
a/2+10/2=a/2+5=b
b=5+a/2