Answer: 35
the age of Roberto is x (x > 3)(x ∈ N)
because Roberto is 3 years older than Carolyn => the age of Carolyn is x - 3
in 7 years, the age of Roberto is x + 7; the age of Carolyn is x - 3 + 7 = x + 4
because In 7 years the sum of their ages will be 81 =>
x + 7 + x + 4 = 81
⇔ 2x + 11 = 81
⇔ 2x = 70
⇔ x = 70/2 = 35
=> the age of Roberto is 35
Step-by-step explanation:
Answer:
9 gram/cm³
Step-by-step explanation:
Volume of a square (L³) = 2³ = 8cm³
Volume of a square (L³) = 2³ = 8cm³
But Density = mass/volume
But Density = Mass/Volume
Density = 72grams/8cm³
Density = 9grams/cm³
2-3x=-x-8
-3x=-x-10
-2x=-10
X=5