1) (x + 6.5) - 7.9 = 18.4
x + 6.5 - 7.9 = 18.4
x - 1.4 = 18.4
x = 18.4 + 1.4
x = 19.8

2) (x - 13.8) * 2.6 = 39.52
2.6x - 35.88 = 39.52
2.6x = 39.52 + 35.88
2.6x = 75.4
x = 75.4 / 2.6
x = 29