All ACT Math Resources
Example Questions
Example Question #306 : Equations / Inequalities
Solve for :
Round to the nearest hundredth.
With quadratic equations, you should always start by getting all of your terms to one side of the equation, setting this equal to :
Thus, simplify into:
Now, the next question you need to ask yourself is, "Can this be factored?" In this case, it can. Factor the quadratic expression:
Now, remember that you merely need to set each group equal to . This gives you the two values for :
; therefore
Likewise, for the other group,
Example Question #301 : Equations / Inequalities
Solve for :
With quadratic equations, you should always start by getting all of your terms to one side of the equation, setting this equal to :
Thus, simplify into:
Now, the next question you need to ask yourself is, "Can this be factored?" In this case, it can, though we are sometimes a bit intimidated by terms that have a coefficient like this. Factor the quadratic expression:
If you FOIL this out, you will see your original equation.
Now, remember that you merely need to set each group equal to . This gives you the two values for :
For the other group, you get .
Example Question #301 : Equations / Inequalities
Solve for :
With quadratic equations, you should always start by getting all of your terms to one side of the equation, setting this equal to :
Thus, simplify into:
Now, the next question you need to ask yourself is, "Can this be factored?" In this case, it cannot be easily factored. Therefore, you should use the quadratic formula. Recall that its general form is:
For our data, , , and .
Thus, we have:
Simplifying, this is:
Now, simplify.
Example Question #309 : Equations / Inequalities
Solve for :
With quadratic equations, you should always start by getting all of your terms to one side of the equation, setting this equal to :
Thus, simplify into:
Now, the next question you need to ask yourself is, "Can this be factored?" In this case, it cannot be easily factored. Therefore, you should use the quadratic formula. Recall that its general form is:
For our data, , , and .
Thus, we have:
Simplifying, this is:
Since is negative, you know that there is no real solution (given the problems arising from the negative square root)!
Example Question #583 : Algebra
Solve:
None of the other answers
and
and
and
and
and
To solve, we must set it equal to zero. The above expression is of the form , so we can use the quadratic formula:
to solve for the roots which are and
We can check by plugging the roots into the expression and making sure that it equals zero.
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