15
y + 15 = 10
54/6 = 36/y So, y = 4
y = x/k so 15 = 6/k making k = 0.4. when x = 10 y = 10/0.4 ie 25 alternatively y/x = k ie 15/6 = k so k = 2.5; y/10 = 2.5 making y = 25.
4y-9 = 15 4y = 15+9 4y = 24 y = 6
15
Y=-6
y = -6
y + 15 = 10
19
-15 = y/7(x both sides by 7)-105 = y
y = 6
3x-y = 9 2x+y = 6 Add both equations together: 5x = 15 x = 3 and y = 0
54/6 = 36/y So, y = 4
cross multiply 3/6=y/10 30=6y y=5
10y + 8y = 18y = 15 y = 15/18 y = 5/6 = 0.833333.....
y = x/k so 15 = 6/k making k = 0.4. when x = 10 y = 10/0.4 ie 25 alternatively y/x = k ie 15/6 = k so k = 2.5; y/10 = 2.5 making y = 25.