Transcript TwMM 2.5 Intersecting Linear Functions.pptx

Math CC7/8 – Be Prepared
On Desk:
Learning Log:
1. Pencil
2. Calculator
3. Math Journal
4. TwMM Learning Log
1. HW: p. 51, #26-34 (build a
graph), #46-55
2. Learning Check Today!
3. Parent Signatures?
- SP Quiz/Test & SP Learning Log?
4. Partner Quiz – Tomorrow!
Tasks for Today
• Learning Check 2.4 – Writing equations
• Finish Lesson 2.4 ?
• Lesson 2.5 – Intersecting Linear Functions
Learning Check 2.4
CC 7/8 TwMM LC 2.4
Name _____________________ Date _____Pd. ___Score ___/ 4
Show all work where necessary. No work No credit. Circle or box your final answer.
1) Write the equation for the line that has a slope of
𝟐
and passes through the point (3, 8).
𝟑
2) Write an equation for the line passing
through (-1, 2) and (7, 6).
F = ___ p + _____
F = -7.5 p + 1000
R = ___ p + _____
R = 2 p + 300
Hint: Solve for the slope and y-intercept of each and
then write the equations.
F = -7.5 p + 1000
Use substitution!
F = -7.5 p + 1,000
F = -7.5 (50) + 1,000
F = -375 + 1,000
F = 625 people
R=
2 p + 300
Use substitution!
R = 2 p + 300
R = 2 (50) + 300
R = 100 + 300
R = 400 people
F = -7.5 p + 1000
R=
2 p + 300
Solve for p …
F = -7.5 p + 1,000
475 = -7.5 p + 1,000
-1,000
- 1,000
-525 = -7.5 p
-7.5 -7.5
If 475 people attended
70 = p
Big Fun, then it was
probably about a 70%
probability of rain that
day.
F = -7.5 p + 1000
360 ≤ 300 + 2 p
-300
-300
60 ≤ 2 p
2
2
30 ≤ p
R=
2 p + 300
Hint: Use an inequality!
The probability of rain must be
at least 30%.
F = -7.5 p + 1000
R=
2 p + 300
Hint: Break-even point!
Set both equations equal to each other…
F
1,000 – 7.5 p
+7.5 p
1,000
-300
700
9.5
73.6
=
=
=
=
=
=
=
=
R
2 p + 300
+7.5 p
9.5 p + 300
-300
9.5 p
9.5
p
When the
probability of rain is
about 74% the
predicted
attendance will be
the same at each
attraction.
F = -7.5 p + 1000
R=
2 p + 300
If the attendance at Big Fun and Get Reel are equal
when the probability of rain is about 74%...
And attendance goes up at Big Fun when the
probability of rain goes down…
Then Big Fun will have greater attendance than Get
Reel when p < 74% .
And Big Fun will have less attendance than Get Reel
when p > 74%