Question

Difficulty: EasyFunction Definitions, Evaluation, and Custom Operators

For all real numbers xx and yy, the custom operation \diamondsuit is defined by xy=3x2y+1x \diamondsuit y = 3x - 2y + 1. What is the value of 545 \diamondsuit 4?

Answer: 8

Answer

The value of 545 \diamondsuit 4 is 8.
Substituting x=5x = 5 and y=4y = 4 into the operation xy=3x2y+1x \diamondsuit y = 3x - 2y + 1 yields 3(5)2(4)+1=158+1=83(5) - 2(4) + 1 = 15 - 8 + 1 = 8.

Step-by-Step Solution

1
Substitute the operands into the custom operator rule
5 \diamondsuit 4 = 3(5) - 2(4) + 1
The first term 55 corresponds to xx and the second term 44 corresponds to yy in the formula.
2
Simplify the numeric expression
15 - 8 + 1 = 8
Multiply first, then perform subtraction and addition from left to right.

Key Concept

Function Definitions, Evaluation, and Custom Operators
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