Persons younger than 18 years old are not eligible to vote. let a be age in years.
which inequality models this situation?
a.
a < 18 and a may be a negative number
b.
a < 18 and a must be a positive number
c.
a > 18 and a may be a negative number
d.
a > 18 and a must be a positive number
@lloveonedirection

check the picture below.

well, the angle at the vertex d is clearly not a right-angle, let's check for the one at the vertex f which does look like,   however if it's indeed, that means ef is perpendicular to df, in which case their slopes will be negative reciprocal of each other.

so the negative reciprocal of the slope of ef is 1, however the slope of df is not 1, is 1/2, so nope, they're not perpendicular lines.

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step-by-step explanation: