Given the formula y=2x(z+3), find y if z=2 and x=4

Show me how you find y and z and determine what y and z are you i appreciate it : )

Eric has challenged himself to walk 24,000 steps in 4 days. if eric walks the same number of steps each day, which function represents the number of steps eric still needs to walk to reach his goal with respect to the number of days since he started his challenge? a. y = 8,000x − 24,000 b. y = -8,000x + 24,000 c. y = 6,000x − 24,000 d. y = -6,000x + 24,000

Can someone me out here number 4 plz