## RS Aggarwal Class 7 Solutions Chapter 7 Linear Equations in One Variable CCE Test Paper

These Solutions are part of RS Aggarwal Solutions Class 7. Here we have given RS Aggarwal Solutions Class 7 Chapter 7 Linear Equations in One Variable CCE Test Paper.

Other Exercises

Question 1.
Solution:
We have:
x3 + y3 + z3 – 3xyz
= (-2)3 + (-1)3 + (3)3 – 3 x (-2) x (-1) x 3
= – 8 – 1 + 27 – 18 = -27 + 27 = 0

Question 2.
Solution:
Co-efficient of x in the given numbers are
(i) -5y
(ii) 2yz
(iii) $$\frac { -3 }{ 2 }$$ ab

Question 3.
Solution:
We have:
(4xy – 5x2 – y2 + 6) – (x2 – 2xy + 5y2 – 4)
= 4xy – 5x2 – y2 + 6 – x2 + 2xy – 5y2 + 4
= -6x2 – 6y2 + 6xy +10
= -2 (3x2 + 3y – 3xy – 5)

Question 4.
Solution:
We have:
(2x2 – 3y2 + xy) – (x2 – 2xy + 3y2)
= 2x2 – 3y2 +xy – x2 + 2xy – 3y2
= 2x2 – x2 – 3y2 – 3y2 + xy + 2xy
= x2 – 6y2 + 3xy
x2 – 2xy + 3y2 is less than 2x2 – 3y2 + xy by x2 – 6y + 3xy.

Question 5.
Solution:
We have:

Question 6.
Solution:
We have:
(3a + 4) (2a – 3) + (5a – 4) (a + 2)
= {3a (2a – 3) + 4 (2a – 3)} + {5a (a + 2) – 4 (a + 2)}
= (6a2 – 9a + 8a – 12) + (5a2 + 10a – 4a – 8)
= (6a2 – a – 12) + (5a2 + 6a – 8)
= (11a2 + 5a – 20)

Question 7.
Solution:

Question 8.
Solution:
We have:

Question 9.
Solution:
Let the consecutive odd number be
x and (x + 2)
x + (x + 2) = 68
2x + 2 = 68
2x = 68 – 2 = 66
x = 33
The required numbers are 33 and (33 + 2), i.e., 35.

Question 10.
Solution:
Let Reenu’s present age be x
Then, her father’s present age will be 3x
Reenu’s age after 12 years = (x + 12)
3x + 12 = 2x + 24
x = 12
Reenu’s present age = x = 12 yrs
And her father’s age = 3x = (3 x 12) = 36 yrs

Mark (✓) against the correct answer in each of the following :
Question 11.
Solution:

Question 12.
Solution:

Question 13.
Solution:

Question 14.
Solution:
(c) 18
Let the number be x.
According to the equation, we have:
4x = x + 54
⇒ 3x = 54
⇒ x = 18

Question 15.
Solution:
(b) 52°
Let the two complementary angles be x° and (90 – x)°.
According to the equation, we have:
x – (90 – x) = 14
⇒ 2x = 104
⇒ x = 52
(90° – x)° = 90° – 52° = 38°
The larger angle is 52°.

Question 16.
Solution:
(c) 32 m
Let the length and breadth of the rectangle be l m and b m, respectively.
According to the questions, we have:
l = 2b ……(i)
2 (l + b) = 96 …..(ii)
Now, 2 (2b+ b) = 96
⇒ 6b = 96
⇒ b = 16
Length = 16 x 2 m = 32 m

Question 17.
Solution:
(b) 12 years
Let the ages of A and B be x and y years respectively,

Question 18.
Solution:
(i) -2a2 b is a monomial.
(ii) (a2 – 2b2) is a binomial.
(iii) (a + 2b – 3c) is a trinomial.
(iv) In -5ab, the coefficient of a is -5.
(v) In x2 + 2x – 5, the constant term is -5.

Question 19.
Solution:
(i) False.
The coefficient of x is -1.
(ii) False.
The coefficient of x in – 3.
(iii) False.
LHS = (5x – 7) – (3x – 5) = 5x – 7 – 3x + 5 = 2x – 2.
(iv) True.
LHS = (3x + 5y) (3x – 5y)
= 3x (3x – 5y) + 5y (3x – 5y)
= 9x2 – 15xy + 15xy – 25y2
= 9x2 – 25y2
(v) True
(a2 + b2)

Hope given RS Aggarwal Solutions Class 7 Chapter 7 Linear Equations in One Variable CCE Test Paper are helpful to complete your math homework.

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