Evaluate. 42 + 2•7 – (5 • 4 – 15)

42 + 2•7 – (5 • 4 – 15)

= 42 + 14 - (20-15)
= 56 - 5
= 51

To evaluate the given expression, we need to follow the order of operations, which is commonly known as PEMDAS (parentheses, exponents, multiplication and division, and addition and subtraction).

Given expression: 42 + 2•7 – (5 • 4 – 15)

First, we start by simplifying within parentheses:
42 + 2•7 – (5 • 4 – 15)
= 42 + 2•7 – (20 – 15)
= 42 + 2•7 – 5
= 42 + 14 – 5

Next, we perform multiplication from left to right:
= 56 – 5

Finally, we perform addition and subtraction from left to right:
= 51

Therefore, the value of the given expression is 51.