We are asked to evaluate the given expression 3 (r² + t) - r² given that r is equivalent to 2 and t is equivalent to 7. The solution to this problem is shown below:
3 (r² + t) - r² , substitute r=2 and t=7 in the expression
3 (2² + 7) - 2² , perform squared
3 (4+7) -4, perform addition of 4 and 7
3 (11) -4, perform multiplication os 3 and 11
33 - 4, perform subtraction
29
The answer is 29.