GSEB Solutions for Class 7 Mathematics – Brackets (English Medium)
GSEB SolutionsMathsScience
Exercise
Solution 1(1):
[3 + 2{3 × (6 ÷ 2 )}] – 1
= [3 + 2{3 × 3}] – 1
= [3 + 2{9}] – 1
= [3 + 18] – 1
= [21] – 1
= 21 – 1
= 20
Solution 1(2):
[6 + 2{2 × (10 ÷ 2)}] – 4
= [6 + 2{2 × 5}] – 4
= [6 + 2{10}] – 4
= [6 + 20] – 4
= [26] – 4
= 26 – 4
= 22
Solution 1(3):
[3 + 2{2 × (6 ÷ 2)}] – 3
= [3 + 2{2 × 3}] – 3
= [3 + 2{6}] – 3
= [3 + 12] – 3
= [15] – 3
= 15 – 3
= 12
Solution 1(4):
[4 + 3{4 × (6 ÷ 3)}] – 1
= [4 + 3{4 × 2}] – 1
= [4 + 3{8}] – 1
= [4 + 24] – 1
= [28] – 1
= 28 – 1
= 27
Solution 1(5):
[3 + 2{3 × (6 ÷ 2)}] – 2
= [3 + 2{3 × 3}] – 2
= [3 + 2{9}] – 2
= [3 + 18] – 2
= [21] – 2
= 21 – 2
= 19
Solution 1(6):
[4 + 5{2 × (5 – 1)}] – 4
= [4 + 5{2 × 4}] – 4
= [4 + 5{8}] – 4
= [4 + 40] – 4
= [44] – 4
= 44 – 4
= 40
Solution 1(7):
[3 + 4{2 × (3 – 1)}] + 7
= [3 + 4{2 × 2}] + 7
= [3 + 4 × {4}] + 7
= [3 + 16] + 7
= [19] + 7
= 19 + 7
= 26
Solution 1(8):
[1 + 2{3 × (4 – 3)}] × 2
= [1 + 2{3 × (1)}] × 2
= [1 + 2{3}] × 2
= [1 + 6] × 2
= [7] × 2
= 7 × 2
= 14
Solution 2(1):
a – [a + {a – (a + 2)} + 2]
= a – [a + {a – a – 2)} + 2]
= a – [a + {- 2)} + 2]
= a – [a – 2 + 2]
= a – [a]
= a – a
= 0
Solution 2(2):
3y – [2y – {4 – (y – 2)} – 5]
= 3y – [2y – {4 – y + 2} – 5]
= 3y – [2y – {6 – y} – 5]
= 3y – [2y – 6 + y – 5]
= 3y – [2y + y – 6 – 5]
= 3y – [3y – 11]
= 3y – 3y + 11
= 11
Solution 2(3):
3a – [{3a – (y – 2y)} – 3a] + y
= 3a – [{3a – (-y)} – 3a] + y
= 3a – [{3a + y} – 3a] + y
= 3a – [3a + y – 3a] + y
= 3a – [y] + y
= 3a – y + y
= 3a
Solution 2(4):
[3x2 – {4x – (2x2 + 5x – 3)}] – 5
= [3x2 – {4x – 2x2 – 5x + 3}] – 5
= [3x2 – 4x + 2x2 + 5x – 3] – 5
= [3x2 + 2x2 – 4x + 5x – 3] – 5
= [5x2 + x – 3] – 5
= 5x2 + x – 3 – 5
= 5x2 + x – 8
Solution 2(5):
-x – [x – {-(- x)}]
= -x – [x – {x)}]
= -x – [x – x]
= – x – 0
= (- x)
Solution 3(1):
[6 + 3{4 × (9 – 2)}] + 10
Verification:
[6 + 3{4 × (9 – 2)}] + 10
= [6 + 3{4 × 7}] + 10
= [6 + 3{28}] + 10
= [6 + 84] + 10
= [90] + 10
= 90 + 10
= 100
Solution 3(2):
2[6 + 3{4 × (5 – 1)}] – 8
Verification:
2[6 + 3{4 × (5 – 1)}] – 8
= 2[6 + 3{4 × (4)}] – 8
= 2[6 + 3{16}] – 8
= 2[6 + 48] – 8
= 2[54] – 8
= 108 – 8
= 100
Solution 3(3):
2[9{5 × (7 – 4)} ÷ 3] + 10
Verification:
2 [9{5 × (7 – 4)} ÷ 3] + 10
= 2[9{5 × (3)} ÷ 3] + 10
= 2[9{15} ÷ 3] + 10
= 2[135 ÷ 3] + 10
= 2[45] + 10
= 90 + 10
= 100
Solution 3(4):
[4{8 × (9 ÷ 3)} + 5] – 1
Verification:
[4{8 × (9 ÷ 3)} + 5] – 1
= [4{8 × (3)} + 5] – 1
= [4{24} + 5] – 1
= [96 + 5] – 1
= [101] – 1
= 101 – 1
= 100
Solution 3(5):
[3{7 × (10 ÷ 2)} – 6] + 1
Verification:
[3{7 × (10 ÷ 2)} – 6] + 1
= [3{7 × (5)} – 6] + 1
= [3{35} – 6] + 1
= [105 – 6] + 1
= [99] + 1
= 99 + 1
= 100
Practice – 1
Solution 1:
7 + {3 + (5 – 3)}
= 7 + {3 + 2}
= 7 + {5}
= 7 + 5
= 12
Solution 2:
10 – {8 + (4 ÷ 2)}
= 10 – {8 + 2}
= 10 – 10
= 0
Solution 3:
19 – [30 – {12 + (8 – 3)}]
= 19 – [30 – {12 + 5}]
= 19 – [30 – 17]
= 19 – 13
= 6
Solution 4:
5x – [-{-(-5x)}]
= 5x – [-{5x}]
= 5x + 5x
= 10x
Solution 5:
30 – [{17 + (9 – 4)} + 17]
= 30 – [{17 + 5} + 17]
= 30 – [{22} + 17]
= 30 – [39]
= (-9)
Solution 6:
5 + [18 – {27 – (12 – 3)}] – 6
= 5 + [18 – {27 – (9)}] – 6
= 5 + [18 – {18}] – 6
= 5 + [0] – 6
= 5 – 6
= (-1)
Solution 7:
{(3x2 – 6x + 5) + (2x – 2x2 + 5)} – (x2 – 4x +10)
= {3x2 – 6x + 5 + 2x – 2x2 + 5} – (x2 – 4x +10)
= {3x2 – 2x2 – 6x + 2x + 5 + 5} – (x2 – 4x +10)
= {x2 – 4x + 10} – (x2 – 4x + 10)
= x2 – 4x + 10 – x2 + 4x – 10)
= x2 – x2 – 4x + 4x + 10 – 10
= 0
Solution 8:
3m – {m + 2(5 – m)}
= 3m – {m + 10 – 2m}
= 3m – {-m + 10}
= 3m + m – 10
= 4m – 10
Solution 9:
[{5x – (x + 3y)} – {x + (2x – y)}]
= [{5x – x – 3y} – {x + 2x – y}]
= [{4x – 3y} – {3x – y}]
= [4x – 3y – 3x + y]
= 4x – 3x – 3y + y
= x – 2y
Solution 10:
15 – [3x – {x + (2x + 5) – (x + 3)}]
= 15 – [3x – {x + 2x + 5 – x – 3}]
= 15 – [3x – {x + 2x – x + 5 – 3}]
= 15 – [3x – {2x + 2}]
= 15 – [3x – 2x – 2]
= 15 – [x – 2]
= 15 – x + 2
= 17 – x