This is joanne’s solution for the equation x2 – 10x – 11 = 0
x2 – 10x – 11 = 0
x2 – 10x = 11
x2 – 10x + 25 = 11 + 25
(x – 5)2 = 36
x – 5 = 36 or x – 5= -25
x = 41 x = -20
the solution is x = 41 or x = -20

a) is joanne’s solution correct? why or why not?
b) if joanne’s solution is incorrect, circle and explain her error and show how to do this problem correctly using the complete the square method that was used above.

Joanne’s solution is incorrect

The correct solution in the procedure

Step-by-step explanation:

we have

Group terms that contain the same variable, and move the constant to the opposite side of the equation

Complete the square. Remember to balance the equation by adding the same constants to each side

Rewrite as perfect squares

So far Joanne's procedure was correct, then she was wrong to take the square root on both sides.

take square root both sides

The solution is or

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet