Given:
Mrs. Applegate owns
of the business.
Mrs. Brown owns 3 times as much as Mrs. Charles.
To find:
The fractional part of the business that Mrs. Brown owns.
Solution:
Let Mrs. Charles owns x part of business.
Mrs. Brown owns 3 times as much as Mrs. Charles.
Mrs. Brown owns = 3x part of business.
Mrs. Applegate owns
of the business.




Divide both sides by 4.


Now,
Mrs. Brown owns

Therefore, Mrs. Brown owns
of the business.
The angles of a triangle add to 180 degrees so the remaining angle must be 90°.
This triangle is half a square. It's one of the two tired triangles of trig, the other being half an equilateral triangle, 30°/60°/90°.
X + 3y = 7
x = -3y + 7
2x + 4y = 8
2(-3y + 7) + 4y = 8
-6y + 14 + 4y = 8
-6y + 4y = 8 - 14
-2y = - 6
y = -6/-2
y = 3
x + 3y = 7
x + 3(3) = 7
x + 9 = 7
x = 7 - 9
x = -2
solution is (-2,3)