Question 1

What is the value of $x$ in the equation $x + 5 = 12$?

Accepted Answer

To find the value of $x$ in the equation $x + 5 = 12$, we need to isolate $x$ by transposing $5$ to the right-hand side. This changes the sign of $5$ from positive to negative. So, $x = 12 - 5$, which gives $x = 7$. Substituting $7$ back into the equation gives $7 + 5 = 12$, which is correct.

Question 2

Solve for $y$: $y - 3 = 10$

Accepted Answer

To solve the equation $y - 3 = 10$, we transpose $-3$ to the right side of the equation. When a negative term is transposed, it becomes positive. Therefore, $y = 10 + 3$, which calculates to $y = 13$.

Question 3

Find the solution of the equation $3x = 15$.

Accepted Answer

In the equation $3x = 15$, $3$ is multiplied by $x$. To isolate $x$, we divide both sides of the equation by $3$. Thus, $x = 15 / 3$, which simplifies to $x = 5$.

Question 4

What is the value of $m$ if $\frac{m}{2} = 6$?

Accepted Answer

Given the equation $\frac{m}{2} = 6$, $m$ is divided by $2$. To find the value of $m$, we multiply both sides of the equation by $2$. This gives $m = 6 	imes 2$, so $m = 12$.

Question 5

Which of the following is a simple equation?

Accepted Answer

A simple equation is a condition on a variable containing an equal sign ($=$) where the highest power of the variable is $1$. Among the choices, $2x + 1 = 5$ is a linear equation with one variable, making it a simple equation.

Simple Equations — CBSE Class 7 Mathematics Important Questions & Revision Notes