What value for c will make the expression a perfect square trinomial? x2 – 7x + c

12.25

Step-by-step explanation:

 A perfect square trinomial is written as , where

first term  = square of first term of binomial

second term=2abx=twice the product of both terms of binomial.

and third term 'c'=square of last term of binomial

In the given polynomial , , a=1

and 2ab = 7

When we put value of a =1, we get

Hence, in place of the question mark makes the given polynomial a perfect square trinomial =

reduce the friction between its moving parts

step-by-step explanation:

in fact, by reducing the friction between the moving parts of the machine, it is possible to reduce the energy wasted due to this friction; therefore, more input energy is converted into useful work, and this will improve the efficiency of the machine.

the first one, all those points on the line just make a strait line.