Given that a = 5i + 4j and b = 3i + 7j, evaluate (3a - 8b).

Given that a = 5i + 4j and b = 3i + 7j, evaluate (3a - 8b).

A 9i + 44j
B -9i + 44j
C -9i - 44j
D 9i - 44j

waec 2017 furthermathematics

The correct answer is C. -9i - 44j

= \(3(5i+4j) - 8(3i+7j) = 15i + 12j - 24i -56j\)

= \(-9i - 44j\)

Previous question Next question