5x + 80 = 67
5x = 67 - 80
x = - 13 / 5
25 = 40x + 5
25 - 5 = 40x
20 / 40 = x
1 / 2 = x
5x + 200 = 45x
5x - 45x = - 200 - 40x = - 200
x = - 200 / - 40
x = 5
z - 82 = z
z - z = 82
0 = 82 no cumple
41x + 8x = 7
49x = 7
x = 7 / 49
x = 1 / 7
<img src="https://tex.z-dn.net/?f=%20%5Cfrac%7By%7D%7B2%7D%20%20%3D%2080" />
y = 2(80)
y = 160
<img src="https://tex.z-dn.net/?f=%20%5Cfrac%7Bx%7D%7B5%7D%20%20%2B%2050%20%3D%20120" />
<img src="https://tex.z-dn.net/?f=%20%5Cfrac%7Bx%20%2B%20250%7D%7B5%7D%20%20%3D%20120" />
x + 250 = 5(120)
x = 600 - 250
x = 350
<img src="https://tex.z-dn.net/?f=99%20%3D%20%20%5Cfrac%7Bz%7D%7B10%7D%20%20-%201" />
<img src="https://tex.z-dn.net/?f=99%20%3D%20%20%20%5Cfrac%7Bz%20-%2010%7D%7B10%7D%20" />
99(10) = z - 10
990 - 10 = z
980 = z.