Match the solution set given in inequality notation with the solution set given in interval notation.

x ≤ a → x ∈ (-∞, a]

x < a → x ∈ (-∞, a)

x ≥ a → x ∈ [a, ∞)

x < a → x ∈ (a, ∞)

Therefore:

x ≥ 7.8 → [7.8, ∞)

x < 7.8 → (-∞, 7.8)

x ≤ 7.8 → (-∞, 7.8]

x > 7.8 → (7.8, ∞)

step-by-step explanation:

given perimeter: 28cm

length: 9cm

atp,

2(l+w)=p of the reactangle

2(9+x)=28

18+2x=28

2x=28-18

x=10/2

x=5

therefore width is 5 cm