I don’t understand this question, please can someone help

yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value

51

step-by-step explanation:

73-22=51 the   mass number minus the amount of protons gives you the amount of neutrons

ιт ωαѕ 5¢м вє¢αυѕє 1/4 σf 20 ιѕ 5

αи∂ 5*4=20

нσρє ι ¢συℓ∂ нєℓρ уσυ