Answer:
200 pencils and 120 pens
Step-by-step explanation:
Let the number of pencils be x while pens be y.
Considering the cost of whole purchase then, we get the equation
0.5x+y=220
Considering the number of items bought, then the equation is
x-y=80
Adding the two equations then we have
1.5x=300
x=300/1.5=200
Consideeing that x-y=80 and x is 200 then
200-y=80
y=200-80=120
Therefore, the pencils were 200 and pens 120 pieces
A. X = 3, because (3-2=1) (3+10=13)
1•13 = (13)
The surface area of a sphere is A = 4 π R² .
Sadly, the question doesn't give you 'R', so you have to
back it out of the circumference.
Circumference = π (diameter)
Divide each side by π : Diameter = circumference / π
Radius = 1/2 diameter: Radius = circumference / (2 π)
Area = 4 π R² =
4 π (circumference/2π)² =
4 π (circumference)² / 4 π²
Divide top and bottom by 4π : Area = (Circumference)² / π
Circumference = 37.68 units
Area = (37.68)² square units /π =
<em>451.93 square units</em>
Y=-13. You have to substitute -4 in for x and then solve.