Algebraic Expressions(7th Grade > Mathematics ) Questions and answers for exam Preparation

7th Grade > Mathematics

ALGEBRAIC EXPRESSIONS MCQs

Total Questions : 116 | Page 6 of 12 pages

Question 51. What will be the expression for the sum of numbers p and q, which is subtracted from their product ?

(p + q)pq
pq + (p - q)
pq + p + q
pq - (p + q)

Discuss Question

Answer: Option D. -> pq - (p + q)
:
D
The sum of p and q is p + q.
The product of p and q is pq.
So, when (p+q)is subtracted from pq,
the final expression will bepq - (p + q).

Question 52. Identify the terms of expression 4pq + p - q - r.

4, p, q, r
4pq, p, q, r
4pq, p, -q, -r
4pq, p, -q, r

Discuss Question

Answer: Option C. -> 4pq, p, -q, -r
:
C
The terms in an expression are separated by operator+ (addition). Therefore,terms of the expression 4pq + p - q - r are 4pq, p, -q, and -r.

Question 53. Which of the following is/are monomial(s) in one variable?

2xy
3x + pq - pq
5
3x + y

Discuss Question

Answer: Option B. -> 3x + pq - pq
:
B
An algebraic expression which consists of only one non-zero termis called a monomial. Examples of monomials are as follows:
a) 2xy is a monomial, but it has 2 variables, 'x' and 'y'
b) 3x + pq -pq is nothing but 3x, which is a monomial, with only one variable, that is 'x'.
c) 5 is a constant
d) 3x +y is a binomial, as it has two terms
So, according to the given question, 3x+ pq-pq = 3x, is a monomial in one variable.

Question 54. A monomial added to/subtracted from a monomial is always a monomial.

True
False
y + xy
2 (xy)

Discuss Question

Answer: Option B. -> False
:
B
A monomial added to/subtracted from a monomial is not always a monomial.
For example, 4x - 5y is not a monomial
4x + 5x = 9xis a monomial

Question 55. The

n^{t h}

term of the pattern 1,4,9,16,25...... is _____.

n+3
n+5
n(n-1)
n2

Discuss Question

Answer: Option D. -> n2
:
D
The pattern in the above case is,

1 = 1^{2}

, (1st term; n=1)

4 = 2^{2}

,(2ndterm; n=2)

9 = 3^{2}

(3rdterm; n=3)
and so on.
Similarly, the term at

n^{t h}

position of the pattern will be

n^{2}

Question 56. Choose the correct option which indicates all the like terms in the following expression.

3 x + 5 x + 7 y + 9 x - 4 y

(−4y, 7y)
(7y,−4y),(3x,5x)
(7y,−4y),(3x,5x,9x)
(3x, 5x, 7y)

Discuss Question

Answer: Option C. -> (7y,−4y),(3x,5x,9x)
:
C
Terms containingthesame variables raised to the same powerare called as like terms.

Here,3x, 5xand 9xare like terms.

Similarly, 7yand -4yare like terms.

Question 57.

If 5 is added to three times the product of two numbers $m$ and $n$ , then the expression will be _______.

$5 + m n$
$5 + 3 m n$
$m + 3 n + 5$
$(m n + 5) \times 3$

Discuss Question

Answer: Option B. ->

5 + 3 m n

:
B

An algebraic expression is a mathematical phrase that can contain ordinary numbers, variables $(l i k e x o r y)$ and operators. According to the given question,
Three times the product of two numbers $m$ and $n$ is $3 m n .$
5 is added to three times the product of two numbers $m$ and $n .$
The equation that represents this statement is $5 + 3 m n .$

Question 58.

Choose the option that contains like terms from the following terms.

$12 x, 12 a, 25 p, 25 q, x a n d 12 y .$

$12 x, x$
$12 a, 12 x$
$25 p, 25 q$
$12 a, 25 q$

Discuss Question

Answer: Option A. ->

12 x, x

:
A

The terms which have the same variable raised to the same power but may only differ in numerical coefficient are called like terms.

For example:

$(i) 3 m a n d - 7 m are like terms.$

$(i i) z a n d \frac{3}{2} z are like terms.$

So, among the given set of terms,
$12 x a n d x are like terms.$

Question 59.

What is the coefficient of term $x y^{3}$ in the expression $5 x^{3} + 10 x y^{3}$ ?

10x
10
-10
-1

Discuss Question

Answer: Option B. -> 10
:
B

The coefficient of term $x y^{3}$ in the expression $5 x^{3} + 10 x y^{3}$ is 10.
A coefficient may be either a numerical factor (like 5, -3, 25...) or an algebraic factor (like $x, y, x^{3} y$ ...) or a product of two or more factors (like $3 x y, 5 x^{2} z$ ...) in a term of an algebraic expression.
$∴$ The coefficient of $x y^{3}$ in the expression $5 x^{3} + 10 x y^{3}$ is 10

Question 60.

Observe the pattern given below.

What is the general expression for this pattern?

$\frac{n (n + 1)}{2}$
$\frac{n (n - 1)}{2}$
$n * (n - 1)$
$n^{2}$

Discuss Question

Answer: Option A. ->

\frac{n (n + 1)}{2}

:
A

So the general expression for this pattern is $\frac{n (n + 1)}{2}$ , where n is the next term and n = 1, 2, 3, 4....

[Alternatively, eliminate the options to figure out the correct answer. This is a good method while attending competitive exams where time plays a crucial role.]