Answer:
Step-by-step explanation:
nth term = a +(n-1)d
a3 = 116 ; a + 2d = 116 ---------(i)
a7 = 180; a + 6d = 180 -------(ii)
multiply (ii) by -1. so a will be eliminated
a + 2d = 116 ---------(i)
(ii)*-1 <u>-a - 6d = -180</u> -------(ii) { Now add the two equations}
- 4d = -64
d = -64/-4
d = 16
Plug in the value of d in equation (i),
a + 2*16 = 116
a + 32 = 116
a = 116 - 32
a = 84
12th term = 84 + 11* 16 = 84 + 176 = 260
Answer:
I believe that A is the correct answer.
Step-by-step explanation:
If it is isosceles, than the legs are the same. We will call them X. The formula for the area of a triangle is 1/2 (base * height). But the base and the height are both X. So the area (18) is equal to 1/2 (x * x), or 1/2(x^2). This means that 36 = x^2. Thus, the length of each side is 6 inches. You can check this work by plugging those into the formula for area. You will find that it equals 18.
the answer is C................................
