-7.1-3.2 extract the negative sign and then add the negative numbers -(7.1+3.2) your answer would be -10.3
You can get all the terms on one side, and then solve for x by any means:

Factor out a -2:

Factor this equation:

I will use the AC method. To use it, first multiply a and c (in ax^2 + bx +c):

Now, look for two numbers that multiply to -12 and add to -11. Obviously these numbers are -12 and 1. (-12*1 = -12 and -12+1 = -11). Now, because of rules, you set it up in a Punnett square:
4x^2 -12x
x -3
Now, we find common factors of the terms in rows:
_x_______-3__
4x| 4x^2 -12x
1 | x -3
So, you can use this to write an equivalent expression to the quadratic given:

Now, we known the factors are (solve for x):
3 and -1/4.
Answer:
54 cm
Step-by-step explanation:
The area (A) of an equilateral triangle is
A =
( s is the side length ) then
= 81
( multiply both sides by 4 to clear the fraction )
s²
= 324
( divide both sides by
)
s² = 324 ( take the square root of both sides )
s =
= 18
Thus
perimeter = 3 × 18 = 54 cm
For problems like this you can move the y's on the bottem up top by fliping the sign of the exponent (in this case 7 to -7) and MULTIPLYING it with EVERYTHING on top, then because of properties of multplication you can add the exponents to combine them into one term (in this case add 3 and -7 to get -4)

If any of this does not make sense let me know and ill try to clarify better
Answer:
Choice D - 8cm and 9cm.
Step-by-step explanation:
The other sides are not greater than 13.
A: 5 + 8 = 13
B: 6 + 7 = 13
C: 7 + 2 = 9
However, <u>D is greater than 13 and is the correct answer.</u>
D: 8 + 8 = 16.