Question

Solve the given expression, \[7x-9=16.\]
A. \[x={}^{5}/{}_{3}\]
B. \[x={}^{25}/{}_{7}\]
C. \[x={}^{17}/{}_{5}\]
D. \[x={}^{2}/{}_{3}\]

Answer 1

Hint:Given is an algebraic expression. Rearrange the terms in the question. Make it undergo algebraic operations like subtraction and division and find the value of x.

Complete step-by-step answer:
Given is an algebraic expression, \[7x-9=16,\] with variable ‘x’.
An algebraic expression is built from integer, constants, variables and algebraic operations like addition, subtraction, multiplication, division and exponentiation by an exponent.
We have been given an expression with a variable ‘x’. So we need to find the value of x from the given expression.
\[7x-9=16\]
Let us take (-9) from the LHS of the equation to the RHS of the equation.
It becomes 9 when it goes to RHS.
\[\begin{align}
  & 7x-9=16 \\
 & 7x=16+9 \\
 & 7x=25 \\
\end{align}\]
Cross multiply and we get the value of x.
\[x={}^{25}/{}_{7}.\]
Thus we solved the algebraic expression.
\[\therefore \]Value of \[x={}^{25}/{}_{7}.\]
Thus option B is the correct answer.

Note: In this expression, we have been provided with only one variable ‘x’. So to find the value of one single variable, only one algebraic expression is needed. If we were given 2 variables, then we would require 2 equations to find the value of those variables.