Which step he made an error and what he supposed to do instead?

step 1

Step-by-step explanation:

however the second part of the equation is incorrectly expanded.

-(3y^2 + 6y + 2)

above states (-3y^2 add 6y add 2)

the -3y^2 is correct because a negative variable and positive variable make a negative variable

however; it should be (-3y^2 minus 6y minus 2 instead of add) because when two variables of different signs (negative and positive) are multiplied the resultant should be negative.

d. millimeters per hour.

step-by-step explanation:

we are given that,

carlo used a rain gauge to measure the amount of water his lawn is receiving from the sprinklers.

since, according to the options, we see that,

water cannot be measured by 'miles per hour', 'meters per second' and 'grams per seconds'.

we get that, the water can be measured by 'millimeters per hour'.

hence, the appropriate rate for describing the amount of water is 'millimeters per hour'.