Answer:
Step-by-step explanation:
Q no 4 :
4, 8
1, 5
3, 7
2, 6
Q no 5:
(a)
10x + 1 = 12x - 5
1+5= 12x - 10x
2x = 6
x = 6/2
x = 3
(b)
11x - 15 + 5x - 13 = 180 (angles on a straight line)
11x + 5x - 15 - 13 =180
16x - 27 = 180
16x = 180 + 27
16x = 207
x = 207 / 16
x = 12.9375
<span>The correct answer is n</span>²<span>+3.
Explanation<span>:
We find the first differences between terms:
7-4=3; 12-7=5; 19-12=7; 28-19=9.
Since these are different, this is not linear.
We now find the second differences:
5-3=2; 7-5=2; 9-7=2.
Since these are the same, this sequence is quadratic.
We use (1/2a)n</span></span>²<span><span>, where a is the second difference:
(1/2*2)n</span></span>²<span><span>=1n</span></span>²<span><span>.
We now use the term number of each term for n:
4 is the 1st term; 1*1</span></span>²<span><span>=1.
7 is the 2nd term; 1*2</span></span>²<span><span>=4.
12 is the 3rd term; 1*3</span></span>²<span><span>=9.
19 is the 4th term; 1*4</span></span>²<span><span>=16.
28 is the 5th term: 1*5</span></span>²<span><span>=25.
Now we find the difference between the actual terms of the sequence and the numbers we just found:
4-1=3; 7-4=3; 12-9=3; 19-16=3; 28-25=3.
Since this is constant, the sequence is in the form (1/2a)n</span></span>²<span><span>+d;
in our case, 1n</span></span>²<span><span>+d, and since d=3, 1n</span></span>²<span><span>+3.</span></span>
Answer:
The answer is C
Step-by-step explanation:
