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).