Value of an Expression

Q.

Which one of the following is not a linear equation?

1. 2x – 5 = 8

2. 2x + 2y = 8

3. 23x + z = p + q

4. p = 23 (x + 1) (x - 1)

Q.

A square is made of 5 identical rectangles. The perimeter of each rectangle is 36 cm. What is the area of the square?

Q. Simplify the expression $3(x^2+y^2+xy)+xyz-2xy-30$ and find its value when $x=6$, $y=-7$, and $z=4$.

1. $3x^2$+$3y^2$+$xyz$+$xy-30$ and $15$
2. $3x^2$+$3y^2$+$xyz$-$xy-30$ and $15$
3. $3x^2$+$3y^2$+$xyz$+$5xy-30$ and $30$
4. $3x^2$+$3y^2$+$xyz$+$6xy-30$ and $7$

Q. The length of a rectangle is twice its breadth and the area is 98 sq. units. What is the perimeter of the rectangle

Q.

Question 57

Choose a letter x, y, z, p etc...., wherever necessary, for the unknown (variable) and write the corresponding expressions for the given statement:

${20}^{o}C$ less than the present temperature.

Q. Surface area of a cuboid is given by $A=2(lb+bh+hl).$
If $l=16\text{cm,}b=5\text{cm}$ and $h=2\text{cm},$ then its surface area is ___.

1. $122c{m}^2$
2. $222c{m}^2$
3. $244c{m}^2$
4. $224c{m}^2$

Q. Krishna’s age is twice the sum of Karan and Arjun’s age. If Arjun is 7 years old and Krishna is 40 years old, find the age of Karan.

1. 11 years
2. 13 years
3. 12 years
4. 14 years

Q. The measures of the angles of a quadrilateral are $(p+{25}^{\circ }),2p,(2p-{15}^{\circ })$ and $(p+{20}^{\circ })$. What is the measure of the smallest angle?

1. ${105}^{\circ }$
2. ${65}^{\circ }$
3. ${115}^{\circ }$
4. ${75}^{\circ }$

Q. Length of rectangle is three times its breadth .If the perimeter of the rectangle is 32 cm, find its length and breadth.

1. Length=12 cm , breadth =4 cm.
2. Length=12 cm , breadth =2 cm.
3. Length=6 cm , breadth =4 cm.
4. Length=12 cm , breadth =3 cm.

Q.

Question 3 (ii)

Find the value of the following expression, when x = -1:
-x + 2

Q.

Using the identities of algebraic expressions, Find the following

(i) (a + 9)(a + 9)

(ii) (1.9b + 1.1c)(1.9b - 1.1c)

(iii) (n - 4)(n - 4)

(iv)(-x + y)(-x + y) [4 MARKS]

Q. When added to its half gives 30. The number is _______.

1. 15
2. 45
3. 40
4. 20

Q. The surface area of a cuboid is 1372 ${cm}^2$. If its dimensions (l : b : h) are in the ratio 4 : 2 : 1, then find the length of the cuboid (in cm).

Q.

Find the value of ‘x’ from the equation, 7(x - 5) + 20 = 6 using the method of transposition.

Q. In the equation $y=x^2-2x+2$, what is the value of $y$, if the value of $x=-2$?

1. 2
2. 6
3. 8
4. 10

Q. If x = 1, y = -1, then the value of 5x - 4y is

1. 1
2. 5
3. 9
4. 11

Q. Evaluate the algebraic expression $a{x}^2+b{y}^2-c{z}^2$,

for $x=1$, $y=-1$, $z=2$, $a=-2$, $b=1$ & $c=-2$

1. 5
2. -9
3. 7
4. 11

Q.

For what value of k, we have 7x² - 5x + k = -4, given that x = -2,

1. -42

2. 22

3. 42

4. -22

Q. If A = $2x^2-y+3xy$, B = $x^2+2xy$ and C = 3y + 2xy, then find A - B + C.

Q. If $x=2,y=15andz=20$
The value of $y^x$ is 225

1. True
2. False

Q. If $x=2,y=5andz=4$
Find the value of:

$z^x$

1. 12
2. 17
3. 14
4. 16

Q. Find the length of a rectangle whose area is 40xy square units and breadth is 8𝑥 unit.

1. 5xy unit
2. 5x unit
3. 5y unit
4. 5 unit

Q.

15+5(y-6) = 0

find the value of y with steps.

Q. if a polynomial is defined as P(x) = 2x^​5+ ax⁴+ bx³+ cx²+ dx + e such that​P(0) = 4, ​P(1) = 5, ​P(2) = 8,
P(3) = 13, P(4) = 20 find the value ofP(5).

Q. If the value of the expression 15x - k for x = 1 is 5, then the value of k is

1. 2
2. 10
3. 5
4. 3

Q. There is a 2.5 m broad path along the sides of a swimming pool which is 40 m long and 30 m broad. What is the area of the path?

Q. Calculate the value of k if 5x²-6x-k=5 , when x=3

Q. What's the lateral surface area of the cube if the length of its side is 6 cm?

1. $144c{m}^2$
2. $72c{m}^2$
3. $36c{m}^2$
4. $24c{m}^2$

Q. In the equation $12x+7-6x=4x+11,$ the value of $x$ is.

1. 2
2. 3
3. 4
4. 5

Q.

What value of x will make the equation 4x + 7 = 11, a true statement?

1. 1

2. 2

3. 0

4. -1