Given:
The expression is:
![b^2+20b](https://img.qammunity.org/2022/formulas/mathematics/high-school/gd5724daa1wb2eqixlhcgc5siljw7upyfo.png)
To find:
The a monomial so that the trinomial may be represented by a square of a binomial.
Solution:
If an expression is
, then be need to add square of half of coefficient of x, i.e.,
in the given expression to make in perfect square.
We have,
![b^2+20b](https://img.qammunity.org/2022/formulas/mathematics/high-school/gd5724daa1wb2eqixlhcgc5siljw7upyfo.png)
Here, coefficient of b is 20,so wee need to add square of half of coefficient of b, i.e.,
.
![\left((20)/(2)\right)^2=10^2](https://img.qammunity.org/2022/formulas/mathematics/high-school/3li97cih71mz21b3zjae7bwarn1d2a0iuh.png)
![\left((20)/(2)\right)^2=100](https://img.qammunity.org/2022/formulas/mathematics/high-school/y516rdifc5yuvhekw0bzapuaxk2o0yzvoo.png)
Therefore, we need to add 100 to make
a perfect square binomial.