1. Systems of equations
Internal assessment
3.15

2. Systems of linear equations
part I
Learning objectives
4 December December 2018
I can form and use systems of simultaneous equations and interpret the solution in context

3. substitute each of the points in in turn to get three equations
Determine the equation of the parabola that passes through the three points (0,5), (1,2), and (4,7).
we might remember the general equation of a parabola is y = ax2 + bx + c
substitute each of the points in in turn to get three equations
3 equations
c = 5
a + b + c = 2
16a + 4b + c = 7
3 solutions
a= , b=−4 1 6 , 𝑐=5
now solve these on your calculator
Equation of parabola
now write down the equation of the parabola
𝑦= 7 𝑥 𝑥 6 +5

4. Systems of linear equations
part II
Learning objectives
4 December December 2018
I can form and use systems of simultaneous equations and interpret the solution in context

5. Use this information to determine the unit price for each item.
A technology retailer specialises in selling one model only of smart phones, tablets and laptops. The table gives the number of each item sold, and the total amount received over a period of three consecutive weeks.
Use this information to determine the unit price for each item.
Number of smart phones sold
Number of tablets sold
Number of laptops sold
Total amount received ($)
Week 1 14 9 5
12 459
Week 2 23 11 8
18 601
Week 3 17 18 3
15 534
allocate a variable to each unknown
a = number of smart phones sold
b = number of tablets sold
c = number of laptops sold
Construct a different equation for each week
Solve with technology!
Present the solution is sentences “ the smart phones cost $ “
week 1 14a + 9b + 5c = 12459
week 2 23a + 11b + 8c = 18601
week 3 17a + 18b + 3c = 15534