Como fazer equações em matemática no oitavo ano?

Linet passes through (4.5) and is perpendicular to the line shown on the condirate grid.what is the equation of line t in standard form?

The sum of these consecutive integers is equal to 9 less than 4 times the least of the integer. find the three integers

Scores on the cognitive scale of the bayley-scales of infant and toddler development range from 1 to 19, with a standard deviation of 3. calculate the margin of error in estimating the true mean cognitive scale score, with 99% confidence, if there are 12 infants and toddlers in a sample.