4 unknowns needs 4 equations. I'll call the unknown numbers a,b,c,d in that order left to right.
4 + a = b
a + b = c
b + c = d
c + d = 67
let's use substitution to get rid to combine equations and get rid of variables.
If a + b = c then a = c - b
4 + (c - b) = b
4 + c = 2b
If b + c = d then b = d - c
4 + c = 2(d - c)
4 + c = 2d - 2c
4 + 3c = 2d
then we have c + d = 67 so c = 67 - d
4 + 3(67 - d) = 2d
4 + 201 - 3d = 2d
205 = 5d
d = 41
Should be easy now, subtract backwards.
67 - 41 = 26
41 - 26 = 15
26 - 15 = 11
15 - 11 = 4
4, 11, 15, 26, 41, 67
Ok so you would start by getting rid of the fraction. You should know the steps for that by now but here this is what it would look like
3y/4+10=2y/4 Simplify
3y/4+10=1y/210=-1y I really simplified the last part but this is what it looks like:
- 
= -1y
10=-1yy=-10
Y-3x
Explanation: do 4y-3y which equals 1 which just equals Y. Then do -8x+5x which equals -3x
C: at y=5
The formula is y=mx+b (b meaning the y-intercept) so that +5 is where your y-intercept is gonna be!
