Iam thinking of a number. when it is increasd by 7, it equals 21. what is my number
a. n=28
b. n=14
c. n=7
d. n=147

If X is increased by 7 to make 21
X + 7 = 21
then rearrange the equation to get X
X = 21-7
X = 14(b)

Let the number be x;
x+7=21
Subtracting 7 from each side,
x+7-7=21-7
x=14

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.