I don't understand how to set up ratios

A parallelogram has an interior angle measuring 81º. Which MUST also be the measure of an interior angle of the parallelogram? A) 9°. C) 49° B) 19° D) 99°

How do you write the number 0.21212121 ... As a fraction

What should Andrea conclude about this system of equations?

If two lines are perpendicular what does that mean

Suppose that the water level of a river is 34 feet and that it is receding at a rate of 0.5 foot per day. Write an equation for the water level, w, after d days. In how many days will the water level be 26 feet?

The factor theorem of algebra states that if a polynomial, P (x), is divided by x-a, then the remainder is P (a). Verify the remainder theorem by showing that when x^2-2x-16 is divided by x+3 the remainder is the same as P (-3).

Jane cuts a piece of twine into three pieces. The second pieces is 7 times as long as the first piece, and the third piece is 5 feet longer than the first piece.

Meg has a piece of poster board that is two and two-fifths feet wide. she needs to fold it into three equal sections. how wide will each section be? two-thirds feet four-fifths feet six and two-fifths feet seven and one-fifth feet

If the hot dog eating champion's goal is to eat 1 hot dog every 13 seconds, how many whole hot dogs does he expect to eat in 12 minutes?

What is (8-2x2) to the power of two equal using pemdas?