Answer:
2.49556
Step-by-step explanation:
A=28.27 miles Sq
A= pie r2 = pie r.3 to 2nd power = 28.27 square miles
So... the radiator has 15 liters of 70% antifreeze.. but needs an 80% antifreeze
well, so, you need to drain some and put some with higher percentage, seems to be, you will end up at the same 15 liters, possible the radiator's capacity, of 80% antifreeze
so, the same amount going out, of 70% is the same amount going in, of 100% antifreeze
now.. let's use the decimal format for the percents, or 70% is 70/100 or 0.7 and so on

so.. let's subtract, from the current solution, 0.7x and add 1x or x, our antifreeze concentration amount, should be 12 though
10.5 - 0.7x + x = 12
solve for "x"
Just answers since long and many simplifiction
it's like doing those multiplication memory things that had like 100 questions but now with algebra fractions
5. fourth or

6. third or

7.the answe ris x+3 since it can be factored out of the 5x+15 tingie (second )
8. fourth or

9. fourth or

times
10. third or

11. second or
12. third or 11(x+7)=60