Question

10. Substituting x = - 3 in:
(i) x2 + 5x + 4 gives (-3)2 + 5(-3) + 4 = 9 + 2 + 4 = 15
(ii) x2 - 5x + 4 gives (- 3)2 - 5(-3) + 4 = 9 - 15+ 4 = -2
(iii) x2 + 5x gives (-3)2 + 5(-3) = -9 - 15 = -24​

Answer 1

(2) option is correct .

ans is - 2

Answer 2

Answer

(I) -2

(ii) 28

(iii) -6

Step-by-step explanation:

(I) x²+5x+4 gives (-3)²+5(-3)+4 = 9+2+4= 15

L:H:S = (-3)²+5(-3)+4

=9-15+4 = -2

≠ R:H:S

the correct statement is x²+5x+4 = -2

(ii) x²-5x+4 gives (-3)²-5(-3)+4 = 9-15+4

L:H:S = (-3)²-5(-3)+4

= 9+15+4 = 28

≠ R:H:S

the correct statement is x²-5x+4 = 28

(iii) x²+5x gives (-3)²+5(-3) = 9-15 = -24

L:H:S = (-3)²+5(-3) = 9-15 = -6

≠ R:H:S

the correct statement is x²+5x = -6