What does stage 4 show? O A. A young female cone with fertilized eggs matures into a seed cone. B. Young male cones produce spores using meiosis. C. A spore divides and grows into a pollen grain using mitosis. D. A seed that contains an embryo plant grows into a young pine tree​

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.

: -)

multiply it by 5 in order for you to understand i cant give an exact answer.

yes, because even though a theory has a  lot of evidence to support it, it is not always true