At time x=0, water begins to drain steadily out of a bathtub. After seconds, the water in the tub is cm deep. After seconds, the tub is empty. Write a linear function rule that models the depth of water in the tub y after any number of seconds x.

Angle A = 3x - 10

Angle B = x

Their angle sum = 90° ( complementary angles form 90° )

This can be written in an equation as =

= 3x - 10 + x = 90

= 3x + × + ( -10 ) = 90

= 4x + (-10) = 90

= 4x = 90 + 10 ( transposing-10 from LHS to RHS changes-10 to +10 )

= 4x = 100

= x = 100 ÷ 4 ( transposing ×4 from LHS to RHS changes ×4 to ÷4 )

= x = 25

Angle A = 3x - 10

= 3 × 25 - 10

= 75 - 10

= Angle A = 65°

Angle B = x = 25°

Their sum = 65 + 25 = 90°

Therefore , the complementary angles , Angle A = 65° and Angle B = 25° .