SOLVING BY UNDOING Juan says, “I see the whole thing a different way." Here is how he explains his approach to solving 4(x + 3) = 20, which he calls “undoing": "Instead of distributing first, I want to eliminate the 4 from the left side by undoing the multiplication.

a. What can Juan do to both sides of the equation to remove the 4? Why does this work?

b. Solve the equation using Juan's method. Did you get the same result as David?

c. Why is it appropriate for this method to be called "undoing"?

896.31 cm= km 100cm = 1m 1000m = 1km a) 0.0089631 b) 0.0089631 c) 8.9631 d) 89.631

Since opening night, attendance at play a has increased steadily, while attendance at play b first rose and then fell. equations modeling the daily attendance y at each play are shown below, where x is the number of days since opening night. on what day(s) was the attendance the same at both plays? what was the attendance? play a: y = 8x + 191 play b: y = -x^2 + 26x + 126 a. the attendance was never the same at both plays. b. the attendance was the same on day 5. the attendance was 231 at both plays on that day. c. the attendance was the same on day 13. the attendance was 295 at both plays on that day. d. the attendance was the same on days 5 and 13. the attendance at both plays on those days was 231 and 295 respectively.

Rewrite the following quadratic functions in intercept or factored form. show your work. y = x^2 + 7x + 10