1 / 3

x + 7

A = lw 30 = x(x + 7) 30 = x 2 + 7x -30 -30 0 = x 2 + 7x – 30 0 = ( )( ). A = 30. x. Example 2. The length of a rectangle is 7 more than the width. Its area is 30. Find the dimensions of the rectangle. x + 7.

elin
Download Presentation

x + 7

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. A = lw 30 = x(x + 7) 30 = x2 + 7x -30 -30 0 = x2 + 7x – 30 0 = ( )( ) A = 30 x Example 2. The length of a rectangle is 7 more than the width. Its area is 30. Find the dimensions of the rectangle. x + 7 Use the x-box to factor the trinomial if you can’t do it in your head. x + 10 x – 3 0 = x + 10 -10 -10 -10 = x x – 3 = 0 +3 +3 x = 3 Reject -10 because you cannot have a negative dimension. reject Answer: Length = 3 + 7 = 10 Width = 3

  2. Example 3. Kara has two sisters. One of the sisters is 7 years older than Kara. The other sister is 3 years younger than Kara. The product of Kara's sisters' ages is 24. How old is Kara? (Hint: let x = Kara’s age, and use the sentence in the problem to write an equation to solve.) Let: x = Kara’s age x – 3 = youngest sister’s age x + 7 = oldest sister’s age (x – 3)(x + 7) = 24 x2 + 7x – 3x – 21 = 24 x2 + 4x – 21 = 24 -24 -24 x2 + 4x – 45 = 0( )( ) = 0 x – 5 Answer: Kara is 5 x + 9 x + 9 = 0 -9 -9 x = - 9 x – 5 = 0 +5 +5 x = 5 reject

  3. Let x = a number x2 + 8 = 6x -6x -6x x2 – 6x + 8 = 0 Put into standard form: ax2 + bx + c then factor. Let x = a number x2 – 15 = 2x -2x -2x x2 – 2x – 15 = 0 Put into standard form: ax2 + bx + c then factor. 3) Let x = a number 2x2 + x = 6 -6 -6 2x2 + x – 6 = 0 Let x = a number 4x2 – 7 = 18 -18 -18 4x2 – 25 = 0 5) Let x =1st CI x + 1 = 2nd CI x(x + 1) = 56 x2 + x = 56 -56 -56 x2 + x – 56 = 0

More Related