Test: Constructing expressions - Year 8 MCQ

James scored x goals in the first three matches combined.
In the fourth match, he scored 2 goals, and in the fifth match, he scored 1 goal.
To find the total number of goals, add the goals from all matches: x (first three matches) + 2 (fourth match) + 1 (fifth match) = x + 2 + 1.
Thus, the total number of goals is x + 2 + 1, which matches option C.

Each of the five people starts with x sweets and eats 2 sweets, leaving x - 2 sweets per person.
Since there are 5 people, the total number of sweets not eaten is 5 times the sweets each person has left: 5 × (x - 2) = 5(x - 2).
Thus, the correct expression is 5(x - 2), which matches option A.

Each chess board has 8 × 8 = 64 squares. With x chess boards, the total number of squares is 64 × x = 64x, which matches option A.

One person takes 5 minutes to pick one sack.
If z people work together on the same sack, they share the work, reducing the time to 5/z minutes per sack.
For 20 sacks, the total time is 20 × (5/z) = (20 × 5)/z = 100/z minutes, which matches option B.

A chess board has 8 squares across and 8 squares down, so the total number of squares is 8 × 8 = 64.
This can be written as 8 × 8 or, more concisely, as 8², since 8² = 8 × 8 = 64.
Option C (8²) is the best way to express the number of squares, as it is compact and mathematically equivalent to 8 × 8.

Twice a number x" means 2x. The product of 5 and 2x is 5 × 2x = 10x, which matches option C.

Solution A has a boiling point of x degrees Celsius.
Solution B’s boiling point is 5 degrees higher than Solution A’s, so it is x + 5 degrees.
Solution C’s boiling point is 25 degrees higher than Solution B’s, so it is (x + 5) + 25 = x + 5 + 25 degrees.
Thus, the boiling point of Solution C is x + 5 + 25, which matches option A.

"Twice a number y" is 2y. "Three less than" means subtracting 3 from 2y, hence 2y − 3.

Peter has x brothers. John has two more brothers than Peter, so John has x + 2 brothers, which matches option D.

The quotient of a number w divided by 4" translates to w ÷ 4, which is the same as .