This is what I got as my answer. Hope it helps!
Answer:
-84
Step-by-step explanation:
The formula for the nth term of a geometric progression is
Un = ar^n- 1
The sum of the first six terms of a geometric series (U6) = 21/16
Common ratio = -1/2 ,
a = First term ??
21/16 = a × (-1/2 )^6- 1
21/16 = a ×(-2^-1)^5
21/16 = a × -2^-6
Cross Multiply
16 × a × -2^-6 = 21
a = 21/16 × -2^-6
a = 21/16 ×- 1/2⁶
a = 21/16 × -1/64
a = 21 ÷(-1/4)
a = 21 × -4
a = -84
The first term = 84
Answer:
Given the ratio for dinosaur stamps to airplane stamp, the correct ratio is 18 : 12
Step-by-step explanation:
Dinosaur stamps = 18
Airplane stamps = 12
John wrote:
ratio of dinosaur stamps to airplane stamps = 12 to 18
Correct ratio:
ratio of dinosaur stamps to airplane stamps = 18 : 12
= 18/12
Answer:
The GCF is going to be 30
Step-by-step explanation:
This Is how I find the GCF of 2 numbers. I find the prime factorization first, then I find the common factors and multiply them. Here
The prime factorization of 21, 2 × 3 × 3 × 5= 90
The prime factorization of 28, 2 × 3 × 5 × 7 = 210
The common factors are, 2, 3, and 5. We multiply those to get the GCF.
2 × 3 × 5 = 30
