Step-by-step explanation:
6a
Sn = n/2 [2a + (n-1) d]
(2Sn)/ n = 2a + (n - 1) d
2a + (n-1) d = (2Sn)/n
(n-1) d = (2Sn - 2a)/n


6b

d = ¹/16
7a.
E = (mv²)/2 + mgh
E = m( v²/2 + gh)
E/m = v²/2 + gh
E/m - gh = v²/2
2(E/m - gh) = v²
so

7b.

v = 14 m/s
Answer:
there is traffic on the freeway
a lot of cars on the freeway
Step-by-step explanation:
Answer: 1,278
Step-by-step explanation: 2(18x18)+2 1/2(18x14)
p.e.m.d.a.s. 18x18= 324 18x14= 252
2x324= 648 2.5x252=630
648+630 =1,278
Okay, so let's go over multiplying negative numbers. A positive times a positive is a positive, right? But a negative times a negative is also a positive. Only a negative times a positive (or a positive times a negative) gives you a negative number. So, we know that one of our 2 numbers in this question must be negative; the other must be positive.
Let's now take a look at the factors of -147, starting with the positives. Obviously, -147 and 1 are factors: -147 * 1 = -147. What other factors of -147 are there?
What about 7? Try it: -147 / 7 = -21. So here are two factors: -21, and 7. They multiply to -147. Do they add up to -14? Let's see: -21+7 = 7+(-21) = 7-21= -14. Yup, that works!
Answer: -21 and 7