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.
Multiplication is a way to represent repeated addition. ... Instead, we can write this repeated multiplication using an exponent, which is the number of repeated factors. Exponents are written as a superscript number to the right of the number being multiplied.
Answer:
y-coordinate is 5 or -1.
Step-by-step explanation:
Point A is at (x, 2) and B is at (x+6, 2). Since AB must lie on the line y=2 and be 6 units long. Point C is on the line x = -3 . So let C be at (-3, y).
Since ΔABC is a right angle, then point C must have the same x-coordinate as point A. Therefore, A(-3, 2) and B(2, 2).
The area of ΔABC is 6. So,
9 = 1/2 (b)(h)
where b is the base and h is the height.
so b = 6 and h = AC
Solving this for C gives
9 = 1/2 (6)(AC)
18/6 = AC
3 = AC
9 = 1/2 (6)(AC)
18/6 = AC
3 = AC
Point C must lie 3 units above point A or 3 units below the point A. If it lies 3 units above, then it has a y-coordinate of 2 + 3 = 5.
If it lies 3 units below, it has a y-coordinate 2 - 3 = -1.
Therefore, y-coordinate is 5 or -1.
Step-by-step explanation:
61/8 or 7 and 5/8. I would try either one
