-5x-4y=20 4x-5y=2
Which of the following choices of a will result in a system of linear equations with exactly one solution?

A, a can be any number
B, a can be any number except 0.8
C, a can be any number except -0.8
D, a=0.8

Two angles are complementary. the large angle is 36 more than the smaller angle. what is the measure of the large angle?

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours

Are triangles the congruent? write the congruency statement.what is the congruency that proves they are congruent? what is the perimeter of ∆pqr?