math
posted by dani .
how do i solve this problem 2(2.5B9)=7 and 0.7w+16+4w=27.28

Multiply out the parenthese, and combine similar terms (constants and terms that are multiples of the unknown) on separate sides of the equation. For example
2(2.5B9) = 7
5B 18 = 7
5B = 25
The last step should be obvious.