Writing Inequalities
A number is at least 12.
x≥12
x+5>12x
x>7
4x>20
x>5
You need to score more than 80 points to pass a test. You scored x.
x>80
If you multiply or divide by a negative, you flip the inequality sign.
True
A number is less than 5.
y<5
y−3≤10
y≤13
6n≤30
n≤5
A gym requires members to be at least 13 years old. Let a be age.
a≥13
Which is the solution to 2x+4<10?
A) x<3
B) x>3
C) x<6
D) x>6
Answer: A
A) x<3
A number is no more than 20.
n≤20
x/3<9
x<27
m/5≥2
m≥10
You have $15 and earn $2 per chore. How many chores c do you need to have at least $25?
Inequality: 15+2c≥25
Solution: c≥5
Which inequality represents “a number is no less than 8”?
A) x>8
B) x≥8
C) x<8
D) x≤8
Answer: B
B) x≥8
You need at least $50 to buy a pair of shoes. You have mmm dollars.
m≥50
−2x>6
x<−3 (flip the sign!)
−3y≤12
y≥−4
A taxi charges $3 plus $2 per mile. You have at most $15. How many miles m can you travel?
Inequality: 3+2m≤15
Solution: m≤6
2x+5>3x−1
x<6
The temperature must stay below 32°F to snow. Let t be temperature.
t<32
−x<5
x>−5
x−7≥−10
x≥−3
A cartoonist has 150 pieces of original artwork. He plans to give 30 pieces to his publishers. The rest will be given to contest winners. Each winner will receive at least 3 pieces of artwork.
How many contest winners could there be?
c≤40
There could be up to 40 contest winners.
4−x≤10
x≥−6