2.5(10x - 16) = 5
2.5 is multiplying on the left, then it will divide on the right
10x - 16 = 5/2.5
10x - 16 = 2
16 is subtracting on the left, then it will add on the right
10x = 2 + 16
10x = 18
10 is multiplying on the left, then it will divide on the right
x = 18/10
x = 1.8