Rewrite the statement 19+7/2 x 6+1 by including 2 pairs of brackets to make the total value equal 2

Rose bought a new hat when she was on vacation. the following formula describes the percent sales tax rose paid b=t-c/c

Ibeg you to me 20. a reaction produces 4.93 l of oxygen, but was supposed to produce 1 mol of oxygen. what is the percent yield?

Can someone me with this? i’m not sure what to put for my equations.