Speedy texting 3a: Lydia wants to text at least 8 characters per second, like James, then the equation would be 10r+4=8 could be used to model this situation. Solve this equation for R. 3b: Explain what the variable r represents in the equation given in question 3a.

Speedy Texting

3a. In the equation, 10r + 4 = 8

r = 0.4 or 40%

3b. The variable r represents an independent variable in the equation.  An independent variable is a variable that is not dependent on another variable, instead other variables depend on it.  Whatever its value is changes the value of other variables in the equation.

Step-by-step explanation:

a) Solving the equation:

10r + 4 = 8

10r = 8 - 4

10r = 4

r = 4/10 = 0.4 or 40%

the answer is 15% decrease

use this formula:

p(a\b) = p(a and b)/p(b).

take it from here.