Which function has real zeros at x = 3 and x = 7?
a- f(x) = x^2 + 4x – 21
b- f(x) = x^2 – 4x – 21
c- f(x) = x^2 – 10x + 21
d- f(x) = x^2 – 10x – 21

f(x) = x² - 10x + 21

Step-by-step explanation:

Functions that has real zeros at x = 3 and x = 7 are the function that produces the roots of 3 and 7 after factorising.

Having two roots as given;

x = 3 and

x = 7

If x=3 then x -3 = 0... 1

Similarly;

If x = 7 then x-7 = 0... 2

Multiplying the zero functions in equation 1 and 2 together we have;

f(x) = (x-3)(x-7)

f(x) = x²-7x-3x+21

f(x) = x² - 10x + 21 = 0

The polynomial or quadratic function above gives the required function.

question: how many people can she serve?

answer: she can serve 16.66666667 people. so she can only give 16 people a complete serving.

question: does she have enough ice cream for her guests?

answer: no. explanation: she only has enough for 16 people to have a full serving. however, she can give a 17th person a partial serving.

u = -(6/7)w

step-by-step explanation:

place all values with 'u' on one side of the equation.

4u + 8w = - 3u + 2w

4u + 3u = 2w - 8w

further simplify the equation by solving the addition and subtraction.

7u = - 6w

make 'u' the independent variable by placing its co-efficient on the right-hand side.

u = - (6/7)w