Question

A teacher has determined that the number of students in her Trig class has increased over a 5-year period at a rate of r given by the equation 5r²+14r-3=0. find r
We got r=2
is this right?

Answer 1

no

Answer 2

you get 1/5

Answer 3

harsha can u kindly show how u got the answer?

Answer 4

we had to use quadratic formula.

Answer 5

You have to factorize

Answer 6

Hold on

Answer 7

the equation should be written as 5r^2+15r-r-3

Answer 8

now take 5r and -1 common. then u get 5r(r+3)-1(r+3) then r=-3 or r=1/5 r cant be -ve value

Answer 9

using quadratic formula the equation that we had \[\frac{ -14+or-\sqrt{14^{2}-4(5)(-3)} }{ 10 }\]

Answer 10

i get what harsha is saying but zuru i have no idea what u just said.

Answer 11

i just know it can not be a portion of a student, so 1/5 cant be right

Answer 12

so cant be -3
then u say both answers are wrong?

Answer 13

right

Answer 14

so there is no correct answer for this question?

Answer 15

there is, it just has to be done using quadratic formula.
and I am not sure I got it right

Answer 16

should I ask again using the formula? Im new here so not sure what to do

Answer 17

yes please