Answer:
7
Step-by-step explanation:
7.base of triangle=√(32.5²-28²)
=√4.5(32.5+28)
=√4.5(60.5)
=√272.25
=16.5
area of triangle=1/2 ×16.5×28
=231
volume=231×31=7161 km³
8.
39.4-25=14.4
width=√(30.6²-14.4²)
=√16.2(30.6+14.4)
=√16.2(45)
=√729
=27
volume=(25+39.4)/2 ×27×35
=(64.4)/2×27×35
=32.2×27×35
=30429 cm³
9 ten-thousands is 9*10,000=90,000. 90,000/10 is 9,000, or nine thousands.
The answer is 74 years. do 11/3=3.67. Then 3.67x20 =73.4 and since that .4 is not a full year you would have to round up to 74
I would substitute y = x^2
4y^2 -21y+20=0
