Writing algebraic expressions questions with answers

Questions

1. Question 1One operation in words

   Write down an algebraic expression for the square of $y$.

   Show the worked solution

   1. Step 1: Which operation do the words describe?“The square of y” means y × y, not 2 × y.
   2. Step 2: Write it the right way round$y^{2}$
2. Question 2One operation in words

   Write down an algebraic expression for $12$ times $x$.

   Show the worked solution

   1. Step 1: Which operation do the words describe?“Times” means multiply.
   2. Step 2: Write it the right way round$12x$
3. Question 3Two operations in words

   Write down an algebraic expression for the result of subtracting $m$ from $7$, multiplied by $2$.

   Show the worked solution

   1. Step 1: Do the first operation in the words$7 - m$
   2. Step 2: Then multiply the whole result (keep it in a bracket)$2(7 - m)$
4. Question 4Two operations in words

   Write down an algebraic expression for $m$ divided by $3$, then increased by $6$.

   Show the worked solution

   1. Step 1: Do the first operation in the words$\dfrac{m}{3}$
   2. Step 2: Then add$\dfrac{m}{3} + 6$
5. Question 5Money, ages and shapes

   Hui Min has $$m$. She buys $4$ bowls of laksa at $$6$ each. Write down an expression, in terms of $m$, for the amount of money, in dollars, she has left.

   Show the worked solution

   1. Step 1: Cost of the food = number × price$\mathstrut 4 \times 6 =$ $24$
   2. Step 2: Money left = what she had − what she spent$m - 24$
6. Question 6Money, ages and shapes

   A taxi charges a flag-down fare of $$5$ and $$2$ for every kilometre travelled. Write down an expression, in terms of $d$, for the fare, in dollars, for a trip of $d$ km.

   Show the worked solution

   1. Step 1: The charge for the kilometres travelled$2d$
   2. Step 2: Add the flag-down fare$2d + 5$