Kyra observed that 85% of the students at the library like to read mystery stories. If 30 students at the library did not like r
1 answer:
Set this up as a proportion. If 85% of students like to read mysteries, that means that 15% don't. Therefore, if 30 students don't like mysteries, then 30 students account for 15% of the total number of students. Set it up as a ratio where 30 students = 15% and X students = 85%. Of course in order to use percentages in an equation we have to change them to decimals, .15 and .85 respectively. Then set up the ratio keeping the number of students in alignment and then the percentage of students in alignment (cuz % is not the same as the number of students.) Like this:
Now we cross-multiply to get .15x = 25.5 and x = 170. That means that 170 students like to read mysteries and that also means that 170 accounts for 85% of the total number of students (which is 200).
Now we cross-multiply to get .15x = 25.5 and x = 170. That means that 170 students like to read mysteries and that also means that 170 accounts for 85% of the total number of students (which is 200).
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Change the function into vertex form:
f(x)=x²-10x+16
make a square by (adding half of -10)², which is 25, then subtract it:
f(x)=x²-10x+25-25+16
f(x)=(x-5)²-9
so the vertex is at (5,-9)
another way to do it:
f(x)=x²-10x+16
the vertex is when x=-
, b=-10, a=1 in this case.
x=-(-10/2*1)=5
plug x=5 into the quadratic function, you get f(x)=-9
f(x)=x²-10x+16
make a square by (adding half of -10)², which is 25, then subtract it:
f(x)=x²-10x+25-25+16
f(x)=(x-5)²-9
so the vertex is at (5,-9)
another way to do it:
f(x)=x²-10x+16
the vertex is when x=-
x=-(-10/2*1)=5
plug x=5 into the quadratic function, you get f(x)=-9
Answer: 79.25 miles
Ok done. Thank to me :>
