Mathematics 4024 · O Level · Introduction to algebra

Introduction to algebra — practice question

The diagram shows part of a number grid. A vertical rectangle that surrounds three numbers can be placed anywhere on the grid. The grid extends further downward.
(a)[1]

If $n$ stands for the number at the top of the rectangle, complete the rectangle with expressions, in terms of $n$, for the other two numbers.

(b)[2]

Use your answers to part (a) to show that the difference is always $25$.

(c)[3]

Lena places a rectangle on the grid. She adds together the three numbers inside her rectangle. Their total is $174$. Find the largest number in Lena’s rectangle.

Worked solution & mark scheme

This 6-mark question has a full step-by-step worked solution and mark scheme. One marking point: “The two expressions are $n+5$ and $n+10$.” …

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