Question

show that x=-1 is a zero of the polynomial p(x)=x square+5x+4
plz and fast​

Answer 1

According to the Question

Let the polynomial be

• P(x) = x² + 5x + 4

As it is given that x = -1 is the zero of the given polynomial .

by putting the value of x = -1 in given polynomial we get

→ P(-1) = (-1)² + 5(-1) + 4

→ P(-1) = 1 -5 + 4

→ P(-1) = 5-5

→ P(-1) = 0

Hence showed that x = -1 is a zero of the given polynomial .

Additional Information !!

Some More identities!!

• (a + b)² = a² + b² +2ab

• ( a - b )² = a² + b² -2ab

• ( a² - b² ) = ( a - b ) ( a + b )

• ( a +b +c)² = (a² + b² + c²) + 2(ab + bc +ca)

• (a + b)³ = a³ + b³ + 3ab(a+b)

• (a-b)³ = a³ - b³ -3ab(a-b)

• ( a³ + b³) = (a+b) (a²-ab +b²)

• (a³ - b³) = (a -b) (a² + ab + b²)