1 Linear Equations and Inequalities 1.9 Homework Answers: Required: #1-7 Extra credit: #8-10
Homework Answers: 1.9 #1
#7
#2
#8
#3
#9
#4
#10
#5 #6
Homework Answers: #1 Find and graph the solution set.
7 x − 3 ≥ −31 7 x ≥ −28 x≥− −4 4 −4
Back
Homework Answers: #2 Find and graph the solution set.
80 > 12 x + 8 72 > 12x
6>x Reverse!
x<6 6
Back
Homework Answers: #3 Find and graph the solution set.
7 − 3x < 37 −3x < 30 x > −10 −10
Back
Reverse!
Homework Answers: #4 Find and graph the solution set.
7 − 2 x ≤ 3x − 3 −2 x ≤ 3x − 10 −5 x ≤ −10
Reverse!
x≥2 2
Back
Homework Answers: #5 Find and graph the solution set.
7 x − 15 − 3 x < 14 − 6 x + 11 4 x − 15 < 25 − 6 x 4 x < 40 − 6 x 10 x < 40
x<4 4
Back
Homework Answers: #6 Find and graph the solution set.
4 − 5(4 x − 12) ≤ 144
4 − 20 x + 60 ≤ 144 −20 x + 64 ≤ 144 −20 x ≤ 80
Reverse!
x ≥ −4 −4
Back
Homework Answers: #7 Find and graph the solution set.
3x + 1 <5 −4
3x + 1 > −20 3x > −21 x > −7 −7
Back
Reverse!
Homework Answers: #8* Find and graph the solution set.
−9 x + 2 4 x − 5 ≤ −6 3 −27 x + 6 ≥ −24 x + 30
−3x ≥ 24 x ≤ −8 −8
Back
Cross multiply Reverse!
Reverse!
Homework Answers: #9* Find and graph the solution set.
ax − b > 2c, for a, b, c > 0 ax > 2c + b 2c + b x> a 2c + b a
Back
Homework Answers: #10* The final grade for a class is calculated by taking 75% of the average test score and adding 25% of the homework score. If the scores are out of 100 and a student has a 72 test average, what must the student average on homework to have a final grade of at least 80?
Final grade = 0.75(test) + 0.25(hw) 0.75(72) + 0.25h ≥ 80 54 + 0.25h ≥ 80 0.25h ≥ 26 h ≥ 104 Back
