9:12 PM Tue Oct 25 . . . webassign.net 0 Need Help? Read It Watch It Master It 4. [-/1 Points] DETAILS SPRECALC7 4.4.057. MY NOTES ASK YOUR TEACHER PRACTICE ANO Use the Laws of Logarithms to combine the expression. - 109 ( x + 2 ) 2 + 5 109 ( * 6 ) - 109 ( * 2 - x - 6 ) 3 ] Need Help? Read It Watch It 5. [-/1 Points] DETAILS SPRECALC7 4.4.065. MY NOTES ASK YOUR TEACHER PRACTICE ANOTH Use the Change of Base Formula and a calculator to evaluate the logarithm, correct to six decimal places. Use either natural or comm logarithms. 1092 ( 275 ) Need Help? Read It Watch It 6. [-/1 Points] DETAILS SPRECALC7 4.4.072.MI. MY NOTES ASK YOUR TEACHER PRACTICE ANOTHER Ebbinghaus' Law of Forgetting (Example 4) states that if a task is learned at a performance level Po, then after a time interval t the performance level P satisfies log (P) = log(Po) - clog(t + 1) where c is a constant that depends on the type of task and t is measured in months. Use the Law of Forgetting to estimate a student's score on a biology test two years after he got a score of 88 on a test covering the same material. Assume that c = 0.3 and t is measured in months. (Round your answer to the nearest whole number.) P = Need Help? Read It Watch It Master It 7. [-/13 Points] DETAILS SPRECALC7 4.4.075. MY NOTES ASK YOUR TEACHER9:12 PM Tue Oct 25 * 58 webassign.net Q Need Help? Read It Watch It Master It 7. [-/13 Points] DETAILS SPRECALC7 4.4.075. MY NOTES ASK YOUR TEACHE The magnitude M of a star is a measure of how bright a star appears to the human eye. It is defined by M = -2.5 109 BO where B is the actual brightness of the star and Bo is a constant. (a) Expand the right-hand side of the equation. (b) Use part (a) to show that the brighter a star, the less its magnitude. Suppose Bj and By are the brightness of two stars such that B1