Question

How do you simplify $4a+7+2a$ ?

Answer 1

Hint: Now we know that we can add the terms which have the same variables with the same power. Hence we can add the terms 4a and 2a. We will substitute the addition of the terms 4a and 2a and then rewrite the expression hence we get the required simplified expression.

Complete step by step solution:
Now let us first understand the concepts of constants and variables.
Now constants are numeric values which do not change in the equation. Similarly in an equation we have variables. Variables are the unknown quantities in an equation or variables are quantities that can change over time and are not likely to be constant. Now variables are usually denoted by letters. Hence to form an equation form terms using constants and variables and we generally use algebraic operations such as addition, multiplication, subtraction, division exponents etc.
Now we know how to add and subtract numbers. Let us learn how to use the same operations on variables. Now we can add and subtract the terms with the same variables and same power. For example we can add or subtract the terms 2x and 4x, like we have $2x+4x=6x$. But we cannot perform the same operation on terms like $2x+4y$ or $2{{x}^{2}}+3x$ as the variables or degree of the variables is not the same.
Now consider the given expression $4a+7+2a$ .
We know that we can add 4a and 2a since the variable and degree is the same.
Hence we get $4a+2a=7a$
Hence we get the above expression as $7a+7$
Hence the given expression can be written as $7a+7$

Note:
Now note that unlike addition or subtraction we can multiply the terms with different variables or different degrees. Hence suppose we have terms 4xy and 3z and we want to multiply them then we have $4xy\times 3z=12xyz$ .