Name: ___________________

Date:___________________

kwizNET Subscribers, please login to turn off the Ads!
Email us to get an instant 20% discount on highly effective K-12 Math & English kwizNET Programs!

Grade 7 - Mathematics
4.24 Finding the value of (a-b)2 (Geometrical Proof)

Find the value of (a-b)2

Suppose AC = AF = A units
AB = AG = b units
\ BC = AC - AB = (a - b) units
GF = AF - AG = (a - b) units
HI = BC = (a - b) units and HE = GE = (a - b) units
\ Area of the square HIDE = HI * HE
= (a - b) * (a - b)
= (a - b)2 sq. units ..........I
Area of square HIDE = Area of square ACDF - Area of rectangle ACIG - Area of rectangle GHEF
= AC * AF - AC * AG - GH * GF
= a.a - a.b - (a-b).b
= a2 - ab - b(a-b)
= a2 - ab - ab + b2
= a2 - 2ab + b2 ..........II
\ From I and II

(a - b)2 = a2 - 2ab + b2

Directions: Solve the following problems. Also write at least ten examples of your own.

Name: ___________________

Date:___________________

Grade 7 - Mathematics
4.24 Finding the value of (a-b)2 (Geometrical Proof)

Q 1: (6x-5)2 = _____?
36x2+60x+25
36x2-60x+25
6x2-60x+25

Q 2: (9x-6)2 = _____?
81x2+108x+36
81x2-108x+36
9x2-108x+36

Q 3: (4x-7)2 = _____?
16x2-56x+49
4x2-56x+49
16x2+56x+49

Q 4: (6x-15)2 = _____?
36x2-180x+225
36x2+180x+225
36x2-180x+25

Question 5: This question is available to subscribers only!

Question 6: This question is available to subscribers only!


Subscription to kwizNET Learning System costs less than $1 per month & offers the following benefits:

  • Unrestricted access to grade appropriate lessons, quizzes, & printable worksheets
  • Instant scoring of online quizzes
  • Progress tracking and award certificates to keep your student motivated
  • Unlimited practice with auto-generated 'WIZ MATH' quizzes
  • Child-friendly website with no advertisements


© 2003-2007 kwizNET Learning System LLC. All rights reserved. This material may not be reproduced, displayed, modified or distributed without the express prior written permission of the copyright holder. For permission, contact info@kwizNET.com
For unlimited printable worksheets & more, go to http://www.kwizNET.com.