Answer:
81 students.
Step-by-step explanation:
If 10% of the 90 students were absent, then that means that 9 students were absent. To find the number of students present, simply subtract.
90 - 9 = 81.
- Hope this helped.
A real world example could be:
Consider x is time in minutes
Consider y is the amount of fish food required in grams
The equation could then represent how much food (in grams) that a fish needs to be fed x minutes after it was previously fed.

is given
here ,
or,

or,

or,7x²+3x-4=-4
or,7x²+3x=0
or,x(7x+3)=0
Either,x=0| Or,7x+3=0
|or,7x=-3
|or,x=

So , the solution set is S={0,-

}
No because a right triangle always has a right angle