Answer:
See below.
Step-by-step explanation:
I will assume that 3n is the last term.
First let n = k, then:
Sum ( k terms) = 7k^2 + 3k
Now, the sum of k+1 terms = 7k^2 + 3k + (k+1) th term
= 7k^2 + 3k + 14(k + 1) - 4
= 7k^2 + 17k + 10
Now 7(k + 1)^2 = 7k^2 +14 k + 7 so
7k^2 + 17k + 10
= 7(k + 1)^2 + 3k + 3
= 7(k + 1)^2 + 3(k + 1)
Which is the formula for the Sum of k terms with the k replaced by k + 1.
Therefore we can say if the sum formula is true for k terms then it is also true for (k + 1) terms.
But the formula is true for 1 term because 7(1)^2 + 3(1) = 10 .
So it must also be true for all subsequent( 2,3 etc) terms.
This completes the proof.
Cross multiply.
75 / x = 25 / 35
25x = 35(75)
25x = 2625
/25 /25
x = 105
Therefore 105 students liked skating.
Proof:
105 + 35 = 140.
140 * 0.75 = 105
140 * 0.25 = 35
140 (total) split into quarters.
35 + 35 + 35 + 35 = 140
35 + 35 + 35 = 105 (3 quarters liked)
35 = 35 (1 quarter disliked)
Odd no. 3/6 = 1/2
less than 4 3/6 = 1/2
The answer is 10 1/2.
First you need to convert 4/5 and 7/10 so the denominator is the same. 4/5=8/10, 7/10 stays the same.
Now we add= 6 8/10 +3 7/10 =9 15/10.
9 15/10=10 5/10=10 1/2.
Hope this helps and hope you have a great day and please make brainiest
