- We know, sum of all angles of a triangle is 180°.
- Therefore, by the problem
72 + 64 + (4x+20) = 180
or, 156 + 4x = 180
or, 4x = 180 - 156
or, 4x = 24
or, x = 24 ÷ 4 = 6
<h3><em>Your </em><em>answer </em><em>is </em><em>6</em><em>.</em></h3>
Given:
second term = 18
fifth term = 144
The nth term of a geometric sequence is:
Hence, we have:
Divide the expression for the fifth term by the expression for the second term:
Substituting the value of r into any of the expression:
Hence, the explicit rule for the sequence is:
The difference (subtraction) of 6 times a number (x represents number) and 7. This gives us 6x-7. That is equal to five times (multiplication) the sum (addition) of the number, x, and 4. This gives you = 5(x+4) and combined gives us B, 6x-7=5(x+4).
