Triangular sequence = n(n + 1)/2
If 630 is a triangular number, then:
n(n + 1)/2 = 630
Then n should be a positive whole number if 630 is a triangular number.
n(n + 1)/2 = 630
n(n + 1) = 2*630
n(n + 1) = 1260
n² + n = 1260
n² + n - 1260 = 0
By trial an error note that 1260 = 35 * 36
n² + n - 1260 = 0
Replace n with 36n - 35n
n² + 36n - 35n - 1260 = 0
n(n + 36) - 35(n + 36) = 0
(n + 36)(n - 35) = 0
n + 36 = 0 or n - 35 = 0
n = 0 - 36, or n = 0 + 35
n = -36, or 35
n can not be negative.
n = 35 is valid.
Since n is a positive whole number, that means 630 is a triangular number.
So the answer is True.
Answer:
x=5
y=2
Step-by-step explanation:
-3(4х – 9у – 2 = 0)
=-12x+27y+6
12х - 5у + 38
-12x+27y+6
22y=44
y=2
x:
4x-9(2)-2=
=4x-20
4x=20
x=5
Remember x is x and f(x) is same thing as y.
f(5) = 4
It is same thing as saying, when x = 5, y aka f(x) should be 4. Aka the point (5,4)
Let’s look at D, if x =5 then f(x)=5? No, it should equal 4. So this is wrong. It is also not linear. So NOT D
Lets look at C, if x =5 then
1/5(5)+3 =
5/5 + 3 =
1+3 =
4
So, f(x) aka y = 4. Is this correct? Yes when x =5, y indeed should equal 4, but it is not linear. So NOT C
Lets look at B, if x=5 then,
2^5 -28 =
32 - 28 =
4
So, f(x) aka y = 4. Is this correct? Yes when x =5, y indeed should equal 4, AND it is linear SO THE ANSWER IS B
Check A too, it gets y=14 so thats wrong as it is not 4.
Answer:
D
Step-by-step explanation:
It just is trust
3/8 meters squared because 3/4x1/2 = 3/8m
