Which surface has more friction? A gymnasium or playing outside on grass

A gymnasium

Explanatian: there would be more people using the gym and all of the shoes and feet on the ground would create FRICTION

try using substitution:

x + y - 6 = x - y. (i'm not giving you the exact answer). since 0 = x - y, then sub 0 in the equation with x - y. combine your like terms, and then use inverse operations, and you'll have your answer.

: -)

c. the initial amount of money placed in the savings account