Answer:
12
Step-by-step explanation:
9+3=12. therefore 12 is your answer
The formula for the sum of n terms in an arithmetic progression is:
S = n/2 * (2a + (n-1)d)
Here, the common difference, d, is 8 and the first term, a, is 1. Substituting these into the formula, we get:
S = n/2 * (2*1 + 8(n - 1))
S = n + 4n² - 4n
S = 4n² - 3n
The answer is A.
The second and the third ones
Barry = 92
heidi = h
92 = h + 18
92 - 18 = h + 18 - 18
74 = h
heidi has 74 marbles
X=-1/3, y=-2, therefore the ordered pair is (-1/3, -2)