using algebraic identity find the coefficient of x square x cube x and constant term without actual expansion (X + 5)( x + 6)( X + 7)
Answers
Step-by-step explanation:
Given expression is (X + 5)( x + 6)( X + 7)
This is in the form of the identity (x+a)(x+b)(x+c)
we know that
(x+a)(x+b)(x+c) =x^3+x^2(a+b+c)+(ab+bc+ca)x+abc
here a=5, b=6, c=7
then
(X + 5)( x + 6)( X + 7)=
=x^3+(5+6+7)x^2+(5×6+6×7+7×5)x+(5×6×7)
=x^3+18x^2+(30+42+35)x+(210)
=x^3+18x^2+107x+210
here x^3= x cube
and x^2 = x square
Answer:
Coefficient of x^2 = 18
Coefficient of x = 107
Constant term = 210
Step-by-step explanation:
Given: Expression (x+5)(x+6)(x+7)
To find: Using algebraic identity find the coefficient of x Square x and constant term without actual expansion?
Solution :
Expression (x+5)(x+6)(x+7)
Using algebraic identity,
(x+a)(x+b)=x^2+(a+b)x+ab
Here, a=5 and b=6
(x+5)(x+6)=x^2+(5+6)x+(5)(6)
(x+5)(x+6)=x^2+11x+30
The expression form,
(x+5)(x+6)(x+7)=(x^2+11x+30)(x+7)
Now writing coefficient as,
Coefficient of x^2, 7+11=18
Coefficient of x, 77+30+107
The Constant term, 30*7
marks brainliest answer