Students can Download Class 8 Maths Chapter 5 Squares, Square Roots, Cubes, Cube Roots Ex 5.3 Questions and Answers, Notes Pdf, KSEEB Solutions for Class 8 Maths helps you to revise the complete Karnataka State Board Syllabus and to clear all their doubts, score well in final exams.
Karnataka State Syllabus Class 8 Maths Chapter 5 Squares, Square Roots, Cubes, Cube Roots Ex 5.3
Question 1.
Find the squares of
(i) 31
(ii) 72
(iii) 37
(iv) 166
Answer:
(i) 312 = (30 + 1)2
= 302 + 2 × 30 ×1 + 12
= 900 + 60 +1 = 961
(ii) 722 = (70 + 2)2
= 702 + 2 × 70 × 2 + 22
= 4900 + 280 + 4 = 5184
(iii) 372 = (30 + 7)2
= 302 + 2 × 30 × 7 + 72
= 900 + 420 + 49=1369
(iv) 1662 = (160 + 6)2
= 1602 + 2 × 160 × 6 + 62
= 25600 + 1920 + 36 = 27556
Question 2.
Find the squares of.
(i) 85
(ii) 115
(iii) 165
Answer:
(i) 852 = (80 + 5)2
= 802 + 2 × 80 × 5 + 52
= 6400 + 800 + 25 = 7225
(ii) 1152 = ( 100 + 15)2
= 1002 + 2 × 100 × 15 + 152
= 10,000 + 3000 + 225 = 13225
(iii) 1652=( 150+15)2
= 1502 + 2 × 150 × 15 + 152
= 22500 + 4500 + 225 = 27225
Question 3.
Find the square of 1468 by writing this as 1465 + 3.
Answer:
First find the square of 1465.
\((1465)^{2}=(\overline{146 \times 147}) 25\) [Statement 9 ]
(1465)2 =(146 × 147)25 [Statement 9]
(1465)2 = 2146225
(1465 + 3)2 = 14652 + 2 × 1465 × 3 + 32
= 2146225 + 8790 + 9
(1468)2 = 2155024