What is the value of b^2 - 4ac for the following equation?
5x^2 + 7x = 6
a. 9
b. 81
c. 169

What is the value of x? enter your answer in the box. photo attached.

Marcus and cody both leave the park at the same time, but in opposite directions. if cody travels 6 mph faster than marcus and after 4 hours they are 64 miles apart, how fast is each traveling? solve using rare times time = distance.

Sam opened a money-market account that pays 3% simple interest. he started the account with $7,000 and made no further deposits. when he closed the account, he had earned $420 in interest. how long did he keep his account open?