Answer:
<u>The number of pens = 120 and the number of pencils = 200</u>
Step-by-step explanation:
Let the number of pens x, and the number of pencils is y
the cost of one pen $1, and the cost of one pencil $0.5
The cost of the whole purchase was $220
1 * x + 0.5 * y = 220
x + 0.5 y = 220 ⇒ eq.(1)
there were 80 more pencils than pens
y - x = 80 ⇒ eq.(2)
from eq.(2) x = y - 80
By substitution with x from the last equation at eq.(1)
∴ (y - 80) + 0.5 y = 220
1.5y = 220 + 80 = 300
y = 300/1.5 = 200
x = y - 80 = 200 - 80 = 120
<u>So, the number of pens = 120 and the number of pencils = 200</u>
No. If you divide 69 by 100 you would get 0.69. If you divided 6 by 10 you would get 0.6. Therefore 69/100 and 6/10 is not equivalent.
Answer:
h = -14
Step-by-step explanation:
-7πh = 98π
⇔ -7h = 98 (Just Divide both sides by π)
⇔ h = 98 ÷ (-7) = -14
So if u were to use a calculator, which you probably might need, you would take the radius, square it by 3, multiply by 4 and then divide by 3.
