The answer for this is 3×4+8÷2=10
let's firstly convert the mixed fractions to improper fractions and then add up all four days.
Slopes of perpendicular lines are opposite reciprocals of each other. The slope of the given equation (which is in slope-intercept form) is 1, the invisible coefficient of x. The opposite reciprocal of 1 is -1, thus the slope of a line perpendicular to the line y = x + 4 is -1.
Hope this helps.