Question

Find the value of the expression 5n2
+ 5n - 2 for n = -2.

Answer 1

${5n}^{2} + 5n - 2 \\ n = - 2 \\ 5 \times ({ - 2}^{2} ) + 5 \times - 2 - 2 \\ 5 \times 4 - 10 - 2 \\ 20 - 10 - 2 \\ 20 - 12 \\ = 8$