Question

a = 6,5² : [ $\frac{5}{8}$ + ( 12,5 - 5 ) × $\frac{2}{5}$ ] - 3,75 - 2,75 = ?

Answer 1

A = (65/10)^2 : (5/8 + 7,5 * 2/5) - 65/10 =
   = 4225/100 : (5/8 + 75*2 / 10*5) - 13/2 =
   = 169/4 : (5/8 + 3) - 13/2 =
   = 169/4 : (5+24)/8 - 13/2 =
   = 169/4 * 8/29 - 13/2 =
   = 169*2 / 29 - 13/2 =
   = (676 - 377) / 58 =
   = 299/58