When 54 is added to a number the result is the same as when the number is multiplied by 3. What is the number? Show working out.
2 answers:
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Answer:
(b)
Step-by-step explanation:
A suitable calculator or spreadsheet can find the matrix product for you. Here, the answer choices differ in their upper left term, so we can determine the correct choice by finding the value of that term. It is the dot product of the first row of B and the first column of A.
(5)(3) +(7)(3) +(3)(2) = 15 +21 +6 = 42
This matches choice B.
