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Algebraic Expressions
Question
Simplify these expressions and find their values if x = 3, a = − 1, b = − 2.
(i) 3x − 5 − x + 9 (ii) 2 − 8x + 4x + 4
(iii) 3a + 5 − 8a + 1 (iv) 10 − 3b − 4 − 5b
(v) 2a − 2b − 4 − 5 + a
Solution
(i) 3x − 5 − x + 9 = 3x − x − 5 + 9
= 2x + 4 = (2 × 3) + 4 = 10
(ii) 2 − 8x + 4x + 4 = 2 + 4 − 8x + 4x
= 6 − 4x = 6 − (4 × 3) = 6 − 12 = −6
(iii) 3a + 5 − 8a + 1 = 3a − 8a + 5 + 1
= − 5a + 6 = −5 × (−1) + 6
= 5 + 6 = 11
(iv) 10 − 3b − 4 − 5b = 10 − 4− 3b − 5b
= 6 − 8b = 6 − 8 × (−2)
= 6 + 16 = 22
(v) 2a − 2b − 4 − 5 + a = 2a + a − 2b − 4 − 5
= 3a − 2b − 9s
= 3 × (−1) − 2 (−2) − 9
= − 3 + 4 − 9 = −8
Sponsor Area
Some More Questions From Algebraic Expressions Chapter
(a) What should be added to x2 + xy + y2 to obtain 2x2 + 3xy?
(b) What should be subtracted from 2a + 8b + 10 to get − 3a + 7b + 16?
What should be taken away from 3x2 − 4y2 + 5xy + 20 to obtain
− x2 − y2 + 6xy + 20?
(a) From the sum of 3x − y + 11 and − y − 11, subtract 3x − y − 11.
(b) From the sum of 4 + 3x and 5 − 4x + 2x2, subtract the sum of 3x2 − 5x and − x2 + 2x + 5.
If p = −2, find the value of:
(i) 4p + 7
(ii) −3p2 + 4p + 7
(iii) −2p3 − 3p2 + 4p + 7
Find the value of the following expressions, when x = − 1:
(i) 2x − 7 (ii) − x + 2 (iii) x2 + 2x + 1
(iv) 2x2 − x − 2
If a = 2, b = − 2, find the value of:
(i) a2 + b2 (ii) a2 + ab + b2 (iii) a2 − b2
When a = 0, b = − 1, find the value of the given expressions:
(i) 2a + 2b (ii) 2a2 + b2 + 1
(iii) 2a2 b + 2ab2 + ab (iv) a2 + ab + 2
Simplify the expressions and find the value if x is equal to 2
(i) x + 7 + 4 (x − 5) (ii) 3 (x + 2) + 5x − 7
(iii) 6x + 5 (x − 2) (iv) 4 (2x −1) + 3x + 11
Simplify these expressions and find their values if x = 3, a = − 1, b = − 2.
(i) 3x − 5 − x + 9 (ii) 2 − 8x + 4x + 4
(iii) 3a + 5 − 8a + 1 (iv) 10 − 3b − 4 − 5b
(v) 2a − 2b − 4 − 5 + a
Mock Test Series
Sponsor Area