Which statement is true?

a. all rectangles are quadrilaterals
b. all quadrilaterals are rectangles.
c. all quadrilaterals are parallelograms.
d. all quadrilaterals are squares.

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

If the speed of an electromagnetic wave is 100,000 cm/s and its wavelength is 100 cm, what is its frequency? a) 100,000 cycles per second (hz) b) 1 × 10-3 cycles per second (hz) c) 10,000,000 cycles per second (hz) d) 1,000 cycles per second (hz)

Olga bought a new skirt that cost $20. sales tax is 5%. how much did olga pay, including sales tax? 7.