Standard Mathematics Primary 6 Algebra

In an HDB block, the residents on each of the lower floors are counted by the expression $2x + 3$ and on each of the upper floors by $x - 5$. The total number of residents on $4$ lower floors and $2$ upper floors is $4(2x + 3) - 2(x - 5)$. Simplify this expression.

A 6x + 22
B 6x + 2
C 6x + 7
D 10x + 22
Show Worked Solution

Worked Solution

Step 1: Expand the first bracket: 4(2x + 3) = 4 × 2x + 4 × 3 = 8x + 12.\n Step 2: Expand the second bracket. The minus sign in front means −2 multiplies both terms: −2(x − 5) = −2 × x + (−2) × (−5) = −2x + 10.\n Step 3: Combine: (8x + 12) + (−2x + 10) = 8x − 2x + 12 + 10.\n Step 4: Simplify like terms: 8x − 2x = 6x and 12 + 10 = 22.\n Step 5: Final answer: 6x + 22. Answer: 6x + 22

Correct answer: 6x + 22

Want more questions like this? Superholic Lab has 10,000+ MOE-aligned questions with full worked solutions.

Start Free Trial — 7 Days Free