Question

Subtract b(b2+b-7)+5 from 3b2 - 8 and find the value of expression obtained for b= -3

Answer 1

[tex]3b^2 - 8 -b^3 - b^2 + 7b -5 3b^2 -b^2 -b^3 +7b -13 -b^3 +2b^2 +7b -13 [/tex][tex]3b^2 -8 -(b(b^{2} +b -7) +5) [/tex]

Answer 2

Given

3b²-8

b(b²+b-7) +5

To Find

The value of expression obtained for b= -3

Solution

3b²-8-(b(b²+b-7) +5)

=3b²-8-b³-b²+7b-5

=2b²-8-b³+7b -5

Given , to substitute the value of b=-3

=2×(-3)²-8-(-3)³+7×(-3)-5

=11

The solution for the expression when b=-3 is 11.