Please help me is about polynomials

(x + 3)(x² – 3x + 7)

Step-by-step explanation:

To express x³ + 2x + 21 in the form of (x + 3)(px² + qx + r),

we need to divide (x³ + 2x + 21) by

(x + 3), since (x + 3) is a factor of

(x³ + 2x + 21)

See attached photo on how to divide (x³ + 2x + 21) by (x + 3).

From the attached photo,

(x³ + 2x + 21)/ (x + 3) = x² – 3x + 7

Therefore,

x³ + 2x + 21 => (x + 3)(px² + qx + r)

x³ + 2x + 21 => (x + 3)(x² – 3x + 7)

38.5

step-by-step explanation:

lets say, first number = r

second number = 3r+7

total = 49

(r)+(3r+7)= 49

4r+7 = 49

4r = 42

r = 42/4

r= 10.5

3r+7 = 3(10.5)+7 = 38.5

hope this

-2

7 - 9 = -2

reversed:

-2 + 9 = 7