WRITING
Equations/Inequalities
Equations/Inequalities
5 minus the product of 3 and a number is 7
5 – 3n = 7
–3x + 4 = 34
x = –10
6(x – 1) = 12
x = 3
Graph on a number line:
x ≥ –3
closed point, shaded to the right
Find the circumference of a circle with a radius of 7 cm.
C = 2πr
C = 2(3.14)(7)
C = 43.96 cm
The sum of 3 and twice a number is greater than 50
3 + 2n > 50
w/4 – 21 > –3
w > 72
14t – 4 – 9t > 31
t > 7
Graph on a number line:
x < 5
open point, shaded to the left
Find the circumference of a circle with a diameter of 22 in.
C = πd
C = 3.14(22)
C = 69.08 in
6 less than a number is at most 10
n – 6 ≤ 10
11 – 4z < –1
z > 3
5 + 2(x – 2) = 19
x = 9
Graph on a number line:
2.4 < x
open point, shaded to the right
Write and solve an equation to find the diameter of a circle with a circumference of 15.7 yards.
C = πd
15.7 = 3.14d
5 yd = d
15 is half a number plus 4
15 = 1/2n + 4
z/–4 + 3 = 15
z = –48
–(3n – 5) ≥ 20
n ≤ –5
Graph on a number line:
x = 9
closed point on 9
Write and solve an equation to find the radius of a circle with a circumference of 56.52 mm.
C = 2πr
56.52 = 2(3.14)r
56.52 = 6.28r
9 mm = r
The difference of 12 and a number divided by 5 is at least 3 times the number
(12 - n) / 5 ≥ 3n
x/–3 – 8 ≥ –3
d ≤ –15
42 – 18t = 4(t + 5)
t = 1
Graph on a number line:
4 ≤ x < 10
closed point on 4, shaded right, ends with open point on 10
Find the area of a circle with a radius of 3 feet.
A = πr2
A = (3.14)(3)2
A = 3.14(9)
A = 28.26 ft2