Answer:
B and C
Step-by-step explanation:
All you need to do is find the answer for all of them and see which ones match
Original:
6 + (-4) - 5
6 - 4 - 5
2 - 5
<u><em>-3</em></u>
This is the answer for the original expression, now we need to see which one is the correct match....
A. -(-6 + 4 ) - 5
2 negatives being subtracted gives you a positive
6 + 4 - 5
10 - 5
5
Incorrect, so now we know its not A
B. 6 - 4 - ( -5)
Again 2 negatives give you a positive
6 - 4 + (5)
6 - 9
-3
Correct, so now we know its B
C. 6 - (4 + 5)
PEMDAS so do the parenthesis first
6 - 9
-3
Correct, so now we it's C.
D. 6 + 4 - 56
10 - 56
-46
Incorrect, so now we know its not D
E. -(-6) + (-4) - (-5)
Again, 2 negatives equal a positive
6 - 4 + 5
2 + 5
7
Incorrect so now we know its not E
The correct answer is C
Hope this helped!
Have a supercalifragilisticexpialidocious day!
Here you have an equilateral triangle. Because of this you know that all angles are also the same as each other. We know that the angles in an equilateral triangle are 60°.
so let's set 7x + 4 = 60
Subtract 4 from both sides: 7x = 56
Divide both sides by 7: x = 8
-4 and -9 is the correct answer
There are 108 degrees in each interior angle of a regular pentagon .
I hope that's help !
Answer:
the common ratio is either 2 or -2.
the sum of the first 7 terms is then either 765 or 255
Step-by-step explanation:
a geometric sequence or series of progression (these are the most common names for the same thing) means that every new term of the sequence is created by multiplying the previous term by a constant factor which is called the common ratio.
so,
a1
a2 = a1×f
a3 = a2×f = a1×f²
a4 = a3×f = a1×f³
the problem description here tells us
a3 = 4×a1
and from above we know a3 = a1×f².
so, f² = 4
and therefore the common ratio = f = 2 or -2 (we need to keep that in mind).
again, the problem description tells us
a2 + a4 = 30
a1×f + a1×f³ = 30
for f = 2
a1×2 + a1×2³ = 30
2a1 + 8a1 = 30
10a1 = 30
a1 = 3
for f = -2
a1×-2 + a1×(-2)³ = 30
-10a1 = 30
a1 = -3
the sum of the first n terms of a geometric sequence is
sn = a1×(1 - f^(n+1))/(1-f) for f <>1
so, for f = 2
s7 = 3×(1 - 2⁸)/(1-2) = 3×-255/-1 = 3×255 = 765
for f = -2
s7 = -3×(1 - (-2)⁸)/(1 - -2) = -3×(1-256)/3 = -3×-255/3 =
= -1×-255 = 255
