Distance between two points, d, is given by
where: (x1, y1) = (2, 2) and (x2, y2) = (5, 5)
The two problems are almost identical: you have to set up a system, and then solve it.
In the first case, let 
and 
be, respectively, the number of girls and boys.
We know that 
(the number of girls in the Spanish Club is four more than twice the number of boys). Also, we know that 
(there are 61 students in total).
So, we have the system
We can use the first equation to substitute in the second
And then solve for :
For the second problem, let 
and 
be the number of pins knocked down by, respectively, Carrie and John. Just like before, we have the system
And you can solve it in the very same way we solved the previous one.
Answer:
20
Step-by-step explanation:
3x + x + 100 = 180 (sum of angles on a straight line)
4x = 180-100
4x=80
divide both sides by 4
x=20
The first step for absolute value equations is to isolate the expression contained within the absolute value bars:
3|2x+4|-1 = 11
3|2x+4| = 12
|2x+4| = 4
so |2x+4| is 4 units away from 0 on a number line, but we don't know in which direction -- negative or positive? you'll have two answers.
2x+4 = 4
AND
2x+4 = -4
solve both of those two step equations and you'll get
x = 0
AND
x = -4
so 0 and -4 are your solutions.
