Question

How do you write a variable expression for the word phrase “twice the sum of 15 and a number”?

Answer 1

Hint: We are given a sentence and we have to write a variable expression for the word phrase. For this first we will read the given phrase carefully. Then assume the given thing that is a number, age, quantity etc. as any variable for example let us assume it as x. Then you will write the expression according to the phrase if it says a number is added or subtracted then we will add or subtract that number. In case of twice or thrice is written then we will have to multiply 2 or 3 by using these words and by using these operations we can form the expression.

Complete step-by-step answer:
Step1: We are given an expression “twice the sum of 15 and a number” so first we will assume the number as$x$. As it is given a sum of$15$and a number so we will add$15$into the number.
$ \Rightarrow x + 15$
Step2: As it is given twice the sum of$15$and a number so we will multiply$2$in the whole expression. On multiplication we will get:
$ \Rightarrow 2\left( {x + 15} \right)$

Hence the expression formed is $2\left( {x + 15} \right)$

Note:
In such a type of question students mainly make mistakes in forming the equation. Sometimes they get confused how to write. For this first assume the variable of for the given date whether it is a number, age etc. and then step by step a multiply or add the numbers or digit as instructed in the phrase. This is the only procedure to form the expression.