Answer:
22
Step-by-step explanation:
To solve this we can plug the values in.
-2x-3y+z
-2(4)-3(-7)+(9)
Simplify.
-8+21+9
Add.
22
Answer:
n= 36
Step-by-step explanation:
18=n-18 (add 18 to both sides of the equation, 18 and -18 cancel out)
36=n
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
<span>1/2x+3y/4=5 => (1/2)x + (3/4)y = 5
1/5x+3y/2=2 => (1/5)x + (3/2)y = 2
Eliminate the fractional coefficients: Mult. the first equation by 4 and mult. the second equation by 10:
2x + 15y = 20
</span><span>Multiply the 1st equation by -1:
-</span>2x - 3y = -20
2x + 15y = 20
-------------------
12y = 0, so y = 0. Then the first equation becomes 2x + 3(0) = 20, or
x=10.
Solution is (10,0).
Answer:
Letter B matches the probability.
Step-by-step explanation:
Lucy throws a fair six sided dice.
Probability of the dice landing on a number between 1 and 6 = 
= 
On a number line fraction can be represented by,
An small section (A to B) will represent the fraction =
Therefore, letter B will match the probability of a dice landing on a number between 1 and 6.
