Remember this! The equation that represents a proportional relationship, or a line, is y=kx, where k is the constant of proportionality.
Answer:
4 students
Step-by-step explanation:
The total number of students is given by:
Where N is the total number of students, A is the number of students that have taken Math 2A, B is the number of students that have taken Math 2B, and C is the number of students that have taken Math 2C:
4 students in Group A have taken all three classes.
*The number of students that have taken two classes has be subtracted so those students do not get counted twice
Let his total money be x.
He spent (3/7)*x of his money.
He gave 1/4(x-3/7x) to his sister.
which is : (1/4)*(4/7)*x = (1/7)*x
Now,
How much money he have in the beginning =
(3/7)*x+(1/7)*x+120=x
(4/7)*x+120=x
120=x-(4/7)*x
120=(3/7)*x
x=120*7/3 [cross multiplication]
x=280.
So, Alex had $280 in the beginning.
Vertical angles:
Vertical Angles are the angles opposite each other when two lines cross.
https://www.mathsisfun.com/geometry/vertical-angles.html
The link has a visual of vertical angles.
Adjacent Angles:
Adjacent angles are two angles that share a common vertex point and a common side. They basically sit right next to each other.
https://www.mathsisfun.com/geometry/adjacent-angles.html
The link has a visual of adjacent angles.
Complementary Angles:
Two angles whose measures add to 90º.
Basically, together they make a right angle.
Supplementary Angles:
Two angles whose measures add to 180º.
Basically, together they form a straight line.
