What is the measure of the vertex angle of an isosceles triangle if one of its base angles measures 54°? 108° 126° 72° 63°

An isosceles triangle has same  base angles

 if one of the base angles measure 54 degrees, 2nd is  also 54

And a triangle measures up to 180 degrees.

180 = x + 2(54)

180 = x + 108

x = 72

72 is right option

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yes because there is exactly one y value for every x value

for function there can't be more than one value for every x value

example 2 – simplify: step 1: completely factor both the numerators and denominators of all fractions. step 2: change the division sign to a multiplication sign and flip (or reciprocate) the fraction after the division sign; essential you need to multiply by the reciprocal. step 3 : cancel or reduce the fractions.