If the sequence is quadratic, then the <em>n</em>-th term (<em>n</em> ≥ 1) is
We're given the first four terms,
Using the formula for the <em>n</em>-th term, this turns into a system of equations,
Solve the system:
• Eliminate <em>c</em> :
(4<em>a</em> + 2<em>b</em> + <em>c</em>) - (<em>a</em> + <em>b</em> + <em>c</em>) = 1 - (-4) ===> 3<em>a</em> + <em>b</em> = 5
(9<em>a</em> + 3<em>b</em> + <em>c</em>) - (<em>a</em> + <em>b</em> + <em>c</em>) = 12 - (-4) ===> 8<em>a</em> + 2<em>b</em> = 16
• Multiply the second equation by 1/2 to get 4<em>a</em> + <em>b</em> = 8, then eliminate <em>b</em> and solve for <em>a</em> :
(4<em>a</em> + <em>b</em>) - (3<em>a</em> + <em>b</em>) = 8 - 5 ===> <em>a</em> = 3
• Solve for <em>b</em> and <em>c</em> :
3<em>a</em> + <em>b</em> = 9 + <em>b</em> = 5 ===> <em>b</em> = -4
<em>a</em> + <em>b</em> + <em>c</em> = 3 - 4 + <em>c</em> = -4 ===> <em>c</em> = -3
Then the rule for the <em>n</em>-th term is
PEMDAS , also photo math will answer it
Answer:
Step-by-step explanation:
-5x - 8y = -3
5x + 9y = 3
y = 0
5x + 0 = 3
5x = 3
x = 3/5
(3/5, 0)
Answer:
2.5 hours
Step-by-step explanation:
it takes him 2.5 hours
Answer:
0.7 oz
Step-by-step explanation:
2.25 OZ. + 3.8 OZ. = 6.05 OZ
6.05 oz ÷ 9 = 0.672 oz.
Round to nearest tenth = 0.7 oz