Y varies directly as x and z. Y is equal to 16 when x=2 and z=4,find Y when x=1 and z=7​

2-digit numbers less than 91 which are 1 less than a multiple of 10

Write numerical coefficient of y² in the expression 2x² - 15xy – 7y²

Colby and jaquan are growing bacteria in an experiment in a laboratory. colby starts with 50 bacteria in his culture and the number of bacteria doubles every 2 hours. jaquan starts with 80 of a different type of bacteria that doubles every 3 hours. let x equal number of days. colbys experiment follows the model: a.) y=50*2^x b.) y=50*2^8x c.) y=50*2^12x jaquans experiment follows the model: a.)80*2^x b.)80*2^8x c.)80*2^12x