UNKNOWN

Unknown

Definition Of Unknown

An Unknown in an equation is the variable to be solved.

More About Unknown

The solution of the equation is the value of the unknown.

Examples of Unknown

In x + 7 = 19, x is the unknown. On solving the equation, we get x = 19 - 12 = 7 which is the value of the unknown

Video Examples: Math Worksheet - iCoachMath

Solved Example on Unknown

Ques: Find the values of the unknowns,x and y, from the given system of equations.

- x + y = 4
6x- 5y= -11

Choices:

A. (- 9, 13)
B. (- 9, - 13)
C. (9, 13)
D. (9, - 13)
Correct Answer: C

Solution:

Step 1: y = x + 4 [Rearrange Equation 1.]
Step 2: 6x - 5(x + 4) = -11 [Replace ywith x + 4 in Equation 2.]
Step 3: x - 20 = -11 [Combine like terms.]
Step 4: x = 9 [Add 20 to both sides.]
Step 5: y = 9 + 4 [Substitute x = 9 in the revised Equation 1.]
Step 6: y = 13 [Simplify.]
Step 7: The solution for the linear system is (9, 13).

Quick Summary

Unknowns are represented by variables.
Solving for the unknown means finding the value of the variable.
The solution makes the equation true.

\[ ax + b = c \]

🍎 Teacher Insights

Emphasize the importance of showing work and checking solutions by substituting the value back into the original equation.

🎓 Prerequisites

Basic arithmetic operations
Understanding of equality

Check Your Knowledge

Q1: Solve for x: x + 5 = 12

A. 5 B. 7 C. 12 D. 17

Q2: Solve for y: 2y = 10

A. 2 B. 5 C. 10 D. 20

Frequently Asked Questions

Q: What is the difference between a variable and an unknown?
A: They are often used interchangeably, but an unknown specifically refers to a variable in an equation that we are trying to solve for.

Q: Can an equation have more than one unknown?
A: Yes, but you usually need multiple equations to solve for multiple unknowns (system of equations).