What point is on both lines y=1/2x+3 and y=x+1?

What is the standard deviation of the following data set rounded to the nearest tenth? 3, 17, 18, 15, 12, 21, 9

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

Kyle and elijah are planning a road trip to california. their car travels 3/4 of a mile per min. if they did not stop driving, how many miles could kyle and elijah drove in a whole day? ? 1 day = 24 hours. plzzz write a proportion i will give you 100 points