The triangle defined by three points on the coordinate plane is congruent with the triangle illustrated:
C) (4,2); (8,2); (4,8) because the corresponding pairs of sides and corresponding pairs of angles are congruent.
If we plot these points we can observe that they are congruent, we should also solve for the distance of each point between each other to conclude their congruency.
The answer is 52.80 because the tip is $8.80 and 44.00+8.80=52.80
Think about this. What do the numbers in a coordinate stand for? They stand for X and Y. If you're trying to figure out what the X is, wouldn't you be solving for x? And didn't they just give you an equation? ;) First off, do you see how the "Y" value is given to you in the coordinate? All you have to do is substitute that 3 in for the "y" in the equation! 3=2x+5. Hey.... that looks like a simple equation! First, you need to subtract 5 from the other side of the equation. Now you're left with 2x=-2. Divide both sides by 2, and you get that x=-1. Now, just substitute that "x' value into the coordinate, and your answer should come out to be (-1, 3). :D
Joel = j, Mark = m, Sandra = s
j + m + s = 120
m = 3j
j = 1/2 s --> s = 2j
plug in (substitute) each letter to make it in terms of only j: j + m + s = 120
j + 3j + 2j = 120
6j = 120
6j/6 = 120/6
j = 20
now plug in for the j & s equation:
s = 2j = 2(20) = 40
Therefore Sandra has 40 coins!
The answer would be 10.976.
