Explanation

An exclamation mark (!) expresses strong emotions like surprise, excitement, or anger.

It is used at the end of exclamatory sentences. 

Explanation

Given x = 1:

x² + 1/x² = 1² + 1/1²

= 1 + 1

= 2

Explanation

To solve, subtract 3/7 from 10/7:

10/7 - 3/7 = 7/7 = 1.

Therefore, the missing value is 1.

Explanation

A cube has six equal square faces, each with the same dimensions.

All six faces of a cube are identical squares, making it a regular polyhedron.

Explanation

(x + 3)(x + k) = x^2 + kx + 3x + 3k

= x^2 + (k + 3)x + 3k

No linear term means k + 3 = 0

So, k = -3

Explanation

Let's denote the number as x. The equation based on the given information is:

6.2x + 8 = 31

Step 1: Solve for x

Subtract 8 from both sides:

6.2x = 23

Step 2: Divide by 6.2

x = 23 / 6.2

x = 3.709677...

x ≈ 3.7

Explanation

4 is the highest number that divides 20, 48, and 56 exactly.

Factors:

20 (1,2,4,5,10,20)

48 (1,2,3,4,6,8,12,16,24,48)

56 (1,2,4,7,8,14,28,56).

Common HCF is 4.

Explanation

Materials like cadmium and mercury are harmful and can cause serious health issues, so they are called toxic substances.

Toxic means poisonous or dangerous to living organisms.

Explanation

"Who" is used for people and acts as the subject of the clause.

It correctly introduces the relative clause: "who had hit the enemy."

Explanation

Oppositional Defiant Disorder (ODD) is a psychiatric condition where a person, usually a child, displays persistent anger, irritability, and defiant behavior toward authority figures.

It is marked by aggressiveness, argumentativeness, and intentional annoyance of others.