In the first 10 mins she answered 2/5 of 40 which is 16. The remaining amount is 24 questions and half of that is 12. So she answered 12 questions in 15 mins. Finally you add them to get 28 questions in 25 minutes.

3 0

3 years ago

The quadratic function y = –10x2 + 160x – 430 models a store’s daily profit (y) for selling a T-shirt priced at x dollars. What

asambeis [7]

Answer:

x = 4 or x = 12

Step-by-step explanation:

Given:

y = -10x² + 160x - 430

When y = $50

50 = -10x² + 160x - 430

50 + 430 = -10x² + 160x

480 = -10x² + 160x

-10x² + 160x - 480 = 0

Divide through by -10

x² - 16x + 48 = 0

Solve the quadratic equation using factorization method

+48 = -12 × -4

-16 = -12 -4

Therefore,

-12 and -4 are both factors

x² - 16x + 48 = 0

(x - 4 )(x - 12 ) = 0

x - 4 = 0

x = 4

x - 12 = 0

x = 12

6 0

4 years ago