This is a geometric sequence with common ratio (r) = 2.
an = ar^(n - 1)
a4 = a(2)^(4 - 1) = a(2)^3 = 8a
8a = 80
a = 80/8 = 10
7th term (a7) = 10(2)^(7 - 1) = 10(2^6) = 10(64) = 640
Answer:
74 hope this works if not I'm sorry
Answer:
a. 11x + d
b. 15m + 10n
Step-by-step explanation:
a. 2(4c+5d) + 3(x-3d)
Break the brackets:
2*4c + 2*5d + 3*x - 3*3d
= 8x + 10d + 3x - 9d
Collect like termsL
= 8x + 3x + 10d - 9d
= 11x + 1d
b. 6(3m+n) - 4(m-n)
Break the brackets:
= 6*3m + 6*n - 3*m - 4*(-n)
= 18m + 6n - 3m - (-4n)
= 18m -3m + 6n + 4n
= 15m + 10n
Hope this helped :3
To factor using the reverse of the distributive property, find what common factor the numbers have and what common factor the variables have.
10.
-8x - 16
8 is a factor of both -8 and 16.
The first term has x, but the second term does not, so there is no common variable. The only common factor is 8, or -8.
Factor out a -8:
-8x - 16 = -8(x + 2)
To see if the factorization is correct, multiply the answer using the distributive property. If you get the original expression, then the factorization is correct.
11.
w^2 - 4w
The first term only has a factor of 1. The second term has a 4. There is no common factor between 1 and 4 except for 1, so there is no number you can factor out. The first term has w^2. The second term has w. Both terms have a common factor of w. We can factor out w from both terms.
w^2 - 4w = w(w - 4)
12.
4s + 10rs
4 and 10 have a common factor of 2.
s and rs have a common factor of s.
2 times s is 2s, so the common factor is 2s.
We now factor out 2s
4s + 10rs = 2s(2 + 5r)
