Ex.2.5 Q8 Linear Equations in One Variable Solution - NCERT Maths Class 8

Question

Simplify and solve the linear equation \begin{align}15(y \! - \! 4) \! - \! 2(y \! - \! 9) \! + \! 5(y \! + \! 6) \!= \! 0\end{align}

Video Solution
Linear Equations
Ex 2.5 | Question 8

Text Solution

What is known?

Equation

What is unknown?

Value of the variable

Reasoning:

First open the brackets then transpose variable to one side and constant to another side.

Steps:

\begin{align}15\left( {y \! - \! 4} \right) \! - \! 2\left( {y \! - \! 9} \right) \! + \! 5\left( {y \! + \! 6} \right)& \! = \! 0 \\15y \! - \! 60 \! - \! 2y \! + \! 18 \! + \! 5y \! + \! 30 & \! = \! 0 \\\qquad\text{(Opening } \text{the brackets)}\\ \\18y \! - \! 12 & \! = \! 0 \\18y & \! = \! 12 \\y & \! = \! \frac{{12}}{{18}} \\ & \! = \! \frac{2}{3} \end{align}

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