Homework Answers

A self-service photo centre allows you to make prints of pictures on an A4 size page. Two types of layouts

are available:

nnnnnlayout x: four pictures are fitted on one page, each has size 6 cm by 4 cm

nnnnnlayout y: two pictures are fitted on one page, each has size 15 cm by 9 cm

It costs R30 to print one page with layout x and it costs R40 to print one page with layout y.

You want at least 16 pictures of any size, and you are willing to spend up to R240. Write and graph a

system of inequalities that models the situation. Shade the solution space of the system of inequalities.

Jemima has three boxes whose total weight is 51 1

5 kg. Box B weighs 5 1

2 kg more than box A and box C

weighs 3 1

5 kg more than box B. Choose the correct statement.

[1] Box A weighs 17 5

6 kg.

[2] Box C weighs 21 1

30 kg.

[3] Box A weighs 42 1

2 kg.

[4] Box B weighs 12 1

3 kg.

The equations of three quadratic functions are given below:

(i) y = 2x2 + 12x + 18

(ii) y = −3x2 − 5x + 3

(iii) y = x2 + 2x − 5

Determine the discriminant of each function and the number of x-intercepts that the parabola has. Choose

the correct sentence. The function described in

[1] (i) has no discriminant and the parabola has no x-intercepts

[2] (ii) has a negative discriminant and the parabola has two x-intercepts

[3] (i) has a zero discriminant and the parabola has one x-intercept

[4] (iii) has a positive discriminant and the parabola has one x-intercept

A coffee shop owner blends a gourmet brand of coffee with a cheaper brand. The gourmet coffee usually

sells for R420,00 per kilogram. The cheaper brand sells for R180,00 per kilogram. How much of each type

should be mixed in order to have 30 kilograms of coffee that is worth R240,00 per kilogram?

Choose the correct sentence:

[1] Three quarters of the mass should be from the cheaper brand.

[2] He should order 7,50 kg of the cheaper brand.

[3] A third of the mass should be from the gourmet brand.

[4] He should order 6,14 kg of the gourmet brand.

The value of a car when new is R224 000,00. It is estimated that the value of the car will decrease at the

rate of 11% per year. Answer the following questions:

a. Determine the exponential function that describes the value of the car y years after it was bought.

b. Determine the value of the car six years after it was bought.