A. the data support his hypothesis so he should investigate if the same change happens in the density of solid water

A

Explanation:

His hypothesis is that if the temperature of water is increased, so decrease occurs in the density of liquid water because the volume will increase. The data support his hypothesis so now he wants to check the density of water in solid form with the increase in temperature. He will apply high temperature and investigate the changes occurs in volume. If volume increases it means density decreases and vice versa.

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.

: -)

silty loam

hope this