Answer:
Part 1: Ms Martinez bought 12 Blow Pips
Part 2: 5 TI-83 calculators were purchased.
Part 3: 4 gold fish were bought.
Part 4: 30 students were brought to watch the movies
Explanation:
Part 1
Let x= Blow pops candy
let y= snickers candy
The equations will be:
Equation 1: 0.50 x + 0.60 y = 16.80 eq(i) and
Equation 2: x + y = 30 eq (ii)
Solving these equations simultaneously,
Multiply eq(ii) with 0.50 and subtract from eq(i)
0.50 x + 0.60 y = 16.80
0.50 x + 0.50 y = 15
- - -
----------------------------
0.1 y = 1.8
y= 18
Putting value of y in eq(ii)
x+y= 30
x= 30- 18
x= 12
So, she bought 12 Blow Pops
Part 2
Let x= TI-70 model
let y= TI-83 model
The equations will be:
Equation 1: 40 x + 65 y = 765 eq(i) and
Equation 2: x + y = 16 eq (ii)
Solving these equations simultaneously,
Multiply eq(ii) with 40 and subtract from eq(i)
40 x + 65 y = 765
40 x + 40 y = 640
- - -
----------------------------
0+ 25 y = 125
y= 5
Putting value of y in eq(ii)
x+y= 16
x= 16- 5
x= 11
So, she bought 5 TI-83 calculators.
Part 3
Let x= Tiger Fish
let y= Gold Fish
The equations will be:
Equation 1: 3 x + 4 y = 40 eq(i) and
Equation 2: x + y = 12 eq (ii)
Solving these equations simultaneously,
Multiply eq(ii) with 3 and subtract from eq(i)
3 x + 4 y = 40
3 x + 3 y = 36
- - -
----------------------------
0+ y = 4
y= 4
Putting value of y in eq(ii)
x+y= 12
x= 12- 4
x= 8
So, Micheal bought 4 Gold fish
Part 4
Let x= Students
let y= Adults
The equations will be:
Equation 1: 4 x + 6 y = 180 eq(i) and
Equation 2: x + y = 40 eq (ii)
Solving these equations simultaneously,
Multiply eq(ii) with 4 and subtract from eq(i)
4 x + 6 y = 180
4 x + 4 y = 160
- - -
----------------------------
0+ 2 y = 20
y= 10
Putting value of y in eq(ii)
x+y= 40
x= 40- 10
x= 30
So, Mr Santos brought 30 students to the movies