question_answer

If p = - 2, find the value of:

(a) 4p+7

(b)\[-3{{p}^{2}}+4p+7\]

(c) \[-2{{p}^{3}}-3{{p}^{2}}+4p+7\]

Answer:

When p = ? 2, then,

(a)        4p + 7 = 4 (? 2) + 7 = ? 8 + 7 = ? 1 1

(b) \[3{{p}^{2}}+4p+7=3{{\left( 2 \right)}^{2}}+4\left( 2 \right)+7\]

= ? 3 (4) ? 8 + 7

= ? 12 ? 1 = ? 13 1

(c) \[2{{p}^{3}}3{{p}^{2}}+4p+7\]

\[=2{{\left( 2 \right)}^{3}}3{{\left( 2 \right)}^{2}}+4\left( 2 \right)+7\]

= ? 2 (? 8) ? 3 (4) ? 8 + 7

= 16 ? 12 ? 8 + 7

= 23 ? 20 = 3