For what value of α is (α, 9) a solution of the equation y=2x+1?

Treat (a, 9) as an x and y value

Set the equation equal to 9

9= 2x+1
8= 2x subtract one
4= x divide by 2

a must be equal to four

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.