Answer:
<h3>
Jake is 13 years old</h3>
Step-by-step explanation:
D - age of Dani
J = D+2 - age of Jake
E = 2J = 2(D+2) = 2D+4 - age od Ethan
Z = 2E = 2(2D+4) = 4D+8 - age of Zoe
The sum of their ages is 102:
D + J + E + Z = 102
D + D+2 + 2D+4 + 4D+8 = 102
8D + 14 = 102
-14 -14
8D = 88
÷8 ÷8
D = 11
J = 11+2 = 13
Look this american “ñ” hahaha
this is what you get while graphing the equation ! hopes this helps with your answer !
F(t) = -5t^2 + 20t + 60
-5(t^2 - 4t - 12)
-5(t + 2) (t - 6)
t = -2 or t = 6
6 seconds
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.