Writing Equations
Write the word sentence as an equation: twice a number x equals 9
2x=9
k - 3.6 = 12.14
k = 15.74
13h = 39
h = 3
What does < mean?
Less than
f<7
How many boxes of tissues can you buy with $21 if one box costs $7?
$7x = $21
3.2j = 12.8
j = 4
68 = x - 52
x = 120
Greater than
Katy's birthday is more than 54 days away. If d represents the number of days, write an inequality to represent this situation.
d>54
After paying $4.76 for a sandwich, Ming has $16.88.
How much money did she start?
x - $4.76 = 16.88
2/3t=27
t=40 1/2
g/8 = 16
g = 128
What does
<=
mean
Less than or equal to
When do you use an open circle on a number line for inequalities?
When the inequality is < or >
Write and solve an equation for this situation.
18+x=-40
x=-58
y/2 = 6 1/3
y = 12 2/3
87 = 30 + p
p = 57
What does this symbol mean?
>=
Greater than or equal to
When do you use a closed circle on an inequality number line?
When the inequality symbol is
<= or >=
For washing the dog Julia was given $10.38.Now she has $36.11.
How much money did she have before?
x + $10.38 = $36.11
k + 5.2 + 3.15 = 12
k = 3.65
65 = k - 18
k = 83
What does this symbol mean?
!=
not equal to
The maximum weight, w, that a stepladder can hold is 250 pounds. Write an inequality to represent this situation.
w<=250