Question 1
2 marksSimplify \(3a \times 2b \times a \times b \times b\)
Model answer
\(3 \times 2 = 6\)
\(a \times a = a^2\)
\(b \times b \times b = b^3\)
So \(3a \times 2b \times a \times b \times b = 6a^2b^3\)
Explanation
Multiply the numbers together, then count how many times each letter is multiplied: there are two a's and three b's. Powers show repeated multiplication, so \(a \times a = a^2\) and \(b \times b \times b = b^3\). Do not add the numbers (\(3 + 2 = 5\)) - they are multiplied.
Mark scheme
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2 marks
B2 for \(6a^2b^3\)
B1 for a single term with two of the three parts correct, e.g. \(6a^2b^2\), \(6ab^3\), \(5a^2b^3\) or \(a^2b^3\) with a wrong coefficient; or for \(6 \times a^2 \times b^3\) not fully simplified