Two times the sum of a number and 8 is equal to 6

Acollection of coins has value of 64 cents. there are two more nickels than dimes and three times as many pennies as dimes in this collection. how many of each kind of coin are in the collection?

Aclassmate thinks that solving a system by graphing gives an exact answer when the lines appear to cross at a grid point, but only an approximate answer when they don't. explain why this isn't true.

Asap! will mark brainliest! ( respond asap, it's urgent! : )) what is the slope for equation y =-3x + 8