I could help you but please send me directions!
The equivalent expression to
is 
Step-by-step explanation:
Step 1:
In sums like these, it is easier to take the common term out of the simplification.
In the expression
, the common term between
and
is the term s. So we take the term s as the common factor.
So taking s out of
we get 
Step 2:
If we multiply a positive with a negative we get a negative. S0 

So the equivalent expression to
is 
Cos20=opp/hyp
cos20=19/x
x=19/cos20
When multiplying after you do the first place you add one zero below it before you move onto the 10ths place, you always add one zero if the number has double digits or more
40*

and

4

is the greatest common factor.