2<\/sup> + 0 (-1) + 2 \n(When a = 0, b = -1) \n= 0 – 0 + 2 = 2<\/p>\nQuestion 6. \nSimplify the expressions and find the value if x is equal to 2. \n(i) x + 7 + 4 (x – 5) \n(ii) 3 (x + 2) + 5x – 7 \n(iii) 6x + 5 (x – 2) \n(iv) 4(2x – l) + 3x+ 11 \nAnswer: \n(i) x + 7 + 4 (x -5) \n= x + 7 + 4x – 20 \n= x + 4x + 7 – 20 \n= 5x – 13 (When x = 2) \n= 5 (2) – 13 \n= 10- 13 \n= -3<\/p>\n
<\/p>\n
(ii) 3 (x + 2) + 5x – 7 = 3x + 6 + 5x – 7 \n= 3x + 5x + 6 – 7 \n= 8x – 1 (When x = 2) \n= 16 – 1 = 15<\/p>\n
(iii) 6x + 5 (x – 2) = 6x + 5x – 10 \n= 1 lx – 10 (When x = 2) \n= 11 (2) – 10 = 22- \n= 12<\/p>\n
(iv) 4(2x – 1)+ 3x + 11 \n= 8x + 3x – 4 + 11 \n= 8x + 3x + 11 – 4 \n= 11x + 7 (When x = 2) \nh = 11(2) + 7 \n= 22 + 7 = 29<\/p>\n
Question 7. \nSimplify these expressions and find their values if x = 3, a = -1, b = -2. \n(i) 3x – 5 – x + 9 \n(ii) 2 – 8x + 4x + 4 \n(iii) 3a + 5 – 8a + 1 \n(iv) 10 – 3b – 4 – 5b \n(v) 2a – 2b – 4 – 5 + a \nAnswer: \n(i) 3x-5-x + 9 \n= 3x-x-5 + 9 \n= 2x + 4 (When x = 3) \n= 2(3)+ 4 \n= 6 + 4 \n= 10<\/p>\n
(ii) 2-8x + 4x + 4 \n= -8x + 4x + 4 + 2 \n= (- 8 + 4) x + 6 \n= – 4x + 6 \n(When x = 3) \n= – 4(3) + 6 \n= -12+ 6 =-6<\/p>\n
<\/p>\n
(iii) 3a + 5 – 8a + 1 \n= 3a – 8a + 5 + 1 \n= (3 – 8) a + 6 \n= -5a + 6 \n(When a = – 1) \n= -5 (-1) + 6 \n= 5 + 6= 11<\/p>\n
(iv) 10 – 3b – 4 – 5b = -3b -5b +10-4 \n= (-3 -5) b + 6 = – 8 b + 6 \n(When b = – 2) = – 8 (-2) + 6 \n= 16 + 6 = 22<\/p>\n
(v) 2a – 2b – 4 – 5 + a = \n2a + a – 2b – 4 -5 = 3a – 2b – 9 \n(When a = – 1 and b = -2) = 3 (-1) -2 (-2) -9 = -3 + 4 -9 = -12+ 4 =-8<\/p>\n
Question 8. \n(i) If z = 10, find the value of z3<\/sup> – 3 (z – 10). \n(ii) If p = – 10, find the value of p2<\/sup> – 2p – 100 \nAnswer: \n(i) z3<\/sup> – 3 [z – 10] = 102<\/sup> – 3 [10- 10] \n(When z = 10) \n= 1000 – 3 (0)= 1000<\/p>\n(ii) p2<\/sup> – 2p – 100 \n= (-10)2<\/sup> – 2 (-10) – 100 \n(When p = -10) \n= 100 + 20 – 100 \n= 120 – 100 = 20<\/p>\n <\/p>\n
Question 9. \nWhat should be the value of a if the value of 2x2<\/sup> + x – a equals to 5, when x = 0? Ans: 2x2<\/sup>+ x – a = 5 (Given: x = 0) \n2(0)2<\/sup> + 0 – a = 5 \n0 + 0 – a = 5 \n-a =5 \na = – 5 \nThe value of a = – 5<\/p>\nQuestion 10. \nSimplify the expression and find its value when a = 5 and b = – 3. \n2(a2<\/sup> + ab) + 3 – ab \nAnswer: \n2(a2<\/sup> + ab) + 3 – ab \n= 2 [52<\/sup> + 5(-3)] + 3 -(5) (-3) \n= 2 [25- 15] +3 + 15 \n= 2(10) + 18 \n= 20 + 18 = 38<\/p>\n","protected":false},"excerpt":{"rendered":"These NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.3 Questions and Answers are prepared by our highly skilled subject experts. NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Exercise 12.3 Question 1. If m – 2, find the value of: (i) m – 2 (ii) 3m – 5 (iii) …<\/p>\n
NCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.3<\/span> Read More »<\/a><\/p>\n","protected":false},"author":9,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"default","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"default","adv-header-id-meta":"","stick-header-meta":"default","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","spay_email":""},"categories":[9],"tags":[],"yoast_head":"\nNCERT Solutions for Class 7 Maths Chapter 12 Algebraic Expressions Ex 12.3 - MCQ Questions<\/title>\n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n \n\t \n\t \n\t \n