The 12th term = a + 11d where a is the first term and d is the common difference
a + 11d = 74
The first three terms are a, a + d, a + 2d
a + (a + d) + (a + 2d) = 42
3a + 3d = 42
a + d = 42 / 3 = 14
By subtracting this equation from the T12 equation
(a + 11d) - (a + d) = 74 - 14
10d = 60
d = 6 (the common difference = 6)
a + 6 = 14
a = 14 - 6 = 8 (the first term = 8)
S(n) = n/2 x (2a + (n-1)d)
S(10) = 10/2 x (2x8 + (10-1)x6)
S(10) = 5 x (16 + 54) = 5 x 70 = 350
Answer:
no ty
Step-by-step explanation:
Answer:
$20 per sweater.
Step-by-step explanation:
It is given that,
A store buys 7 sweaters for $42 and sells them for $182.
We need to find how much profit the store make per sweater.
The amount the store bought the sweaters fr is calculated as follows :
$182- $42 = $140
Profit the store made per sweater is given by :
Hence, the store will make $20 per sweater.
Answer:
-35,35,0
Step-by-step explanation:
Let's organise our information :
Now let's add them together :
- x+xy²+x-xy²=250y-240y
- 2x=10y
- x=5y ⇒ y= x/5
Let's replace y by x/5 in the first equation :
- x+x*(x/5)²=250*(x/5)
- x+ (x∧3)/25 = 50x
- 49x-(x∧3)/25=0
- x(49-(x²/25))=0
- x=0 or 49-(x²/25)=0
- x=0 or 49= x²/25
- x=0 or x²=1225
- x=0 or x= or x= -
- x=0 or x=35 or x= -35
so x=[0,35,(-35)]
Combine the similar terms, Add / Subtract x to both sides, Add / Subtract (The term that comes before the equal sigh) to both sides, & <span>Divide both sides by the value that is next to the X variable. </span>