OK. These problems are easy if you know the quadratic formula,
and they're impossible if you don't.
Here's the quadratic formula:
When the equation is in the form of Ax² + Bx + C = 0
then x = [ -B plus or minus √(B²-4AC) ] / 2A
I'm sure that formula is in your text or your study notes,
right before these questions. You should cut it out or
copy it, and tape it inside the cover of your notebook.
Then, you'll always have it when you need it, until
you have it memorized and can rattle it off.
The first question says 3x² + 5x + 2 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes ! A=3 B=5 C=2
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
= [ -5 plus or minus √(5² - 4·3·2) ] / 2·3
= [ -5 plus or minus √(25 - 24) ] / 6
= [ -5 plus or minus √1 ] / 6
x = -4 / 6 = -2/3
and
x = -6 / 6 = -1 .
_______________________________________
The second question says
4x² + 5x - 1 = 0
Is this in the form of Ax² + Bx + C = 0 ?
Yes it is ! A=4 B=5 C= -1
so you can use the quadratic formula to solve it.
x = [ -B plus or minus √(B²-4AC) ] / 2A
Now, you take it from here.
Hello! For these kinds of problems, the formula for finding the principal is I / rt. That means, divide the simple interest by the rate and time (rate should be in decimal form). In order to find simple interest, just do prt, which means multiply the principal (initial amount) by the rate (simple interest rate, in decimal form) by the amount of time (could be in months or years). With that being said, if you solve it correctly, here are your answers:
Principal: $14,181
Interest rate: 10%
Time: 4 years
Simple Interest: $5,672.40
Principal: $83,079
Interest rate: 9%
Time: 2 years
Simple Interest: $14,954.22
Principal: $659,379.96
Interest rate: 11.7%
Time: 28 months
Simple Interest: $179,753.57
Principal: $18,936
Interest Rate: 2.41%
Time: 3 Months
Simple Interest: $114.09
Note: If the time is in months, be sure to convert it into a decimal and multiply. If a decimal repeats, just convert it to the nearest hundredth.
Answer:
Step-by-step explanation:
We can factor the expression by using the common factor.
Pull out 3x from the expression.
Common Factor is similar to dividing by the term we pull out. When we pull out the term, we divide the whole expression and keep the term out of the expression.
Do you need help with the whole worksheet ?
