Yuri wrote twice as many poems as xenia. yuri wrote 3 more poems than xenia. the number of poems written can be represented by the system of equations: y=2x and y=x+3

What is the simplified form of square root of 400 to the 100th power ?

Paco orders an ice cream for $1, but realizes his wallet is at home and he only has 3/20 of $1 with him. if his mom pays the remaining 7/20 of the dollar, how much will she pay? $0.05 $0.15 $0.85 $0.95

Whoever gets this right gets the ! the half life of a soul smelling substance is 4 years. if you have 8 oz of this strange substance, how much of it will you have after 20 years? show work.