These videos might help you
https://www.khanacademy.org/math/algebra/systems-of-linear-equations/systems-of-linear-equations-wor...
Pi r2
17 divide 2=8.5
Then
8.5•8.5=72.25
Then
3.14•72.25=226.865
Then
226.865 divide by 2 =113.4325m2
Answer: $11.80 for another 4 panes of glass.
Step-by-step explanation: We know that 9 panes of glass cost $26.55, but we should first find how many dollars would it cost per pane of glass, or 1.
So, we can divide 26.55 by 9 to find the price per 1 pan of glass.
26.55/9 = 2.95, or $2.95 per pane of glass.
Now, we want to know how much it will cost for 4 panes of glass. Simply multiply 2.95 by 4.
2.95 x 4 = 11.8, or $11.80 for another 4 panes of glass.
Answer: 15 boys
Explanation: ratio 5:7
5 + 7 = 12
Number of boys = 5/12 × 36