Answer:
740
Step-by-step explanation:
The n th term of an arithmetic series is
= a₁ + (n - 1)d
where a₁ is the first term and d the common difference
Given a₃ = 7 and a₇ = (3 × 7) + 2 = 21 + 2 = 23 , then
a₁ + 2d = 7 → (1)
a₁ + 6d = 23 → (2)
Subtract (1) from (2) term by term
4d = 16 ( divide both sides by 4 )
d = 4
Substitute d = 4 into (1)
a₁ + 2(4) = 7
a₁ + 8 = 7 ( subtract 8 from both sides )
a₁ = - 1
The sum to n terms of an arithmetic series is
= 
[ 2a₁ + (n - 1)d ] , thus
= 
[ (2 × - 1) + (19 × 4) ]
= 10(- 2 + 76) = 10 × 74 = 740
If the three slashes are 190, 195, and 200, we can see it as
<span>-l----------l--------|--l- with the slightly longer line being around 198.78. Since it is clearly closer to the end of the line than the start of the line, we round it to 200</span>
Answer:
1. x + y = 180
2. x = 50 y= 130
Step-by-step explanation:
They're parallel.
We can label the unamed angle z.
So z = y
and 50 = x
There's 360 degrees in a circle, so x + y= 180 because it's half 360 and half a circle.
x=50
so 50 + 50 = 100.
360 - 100 = 260
so 260 ÷ 2 = 130
y = 130 because y and z are equal so they're the same number
Y = (1/5)x -2
for a perpendicular line, you make the slope the reciprocal of the other equation
