Answer:
561
Step-by-step explanation:
an = dn - (a-d)
The difference is 3.
The first term is 12.
an = 3n - (12-3)
an = 3n - 9
Put n as 1, 2, 3, 4, 5 ....22.
3(1) - 9 = -6
3(2) - 9 = -3
3(3) - 9 = 0
3(4) - 9 = 3
3(5) - 9 = 6
...
3(22) - 9 = 57
Add the first 22 terms.
-6+-3+0+3+6+9+12+15+18+21+24+27+30+33+36+39+42+45+48+51+54+57
= 561
Answer:
x = 18 and y = 6√10
Step-by-step explanation:
First using pythagoras theorem on the small triangle
h² = 6² + 2²
h² = 36 + 4
h² = 40
h= √40
h = √4 * 10
h = 2√10
Using the similarity theorem;
y/2√10 = 6/2
y/√10 = 6
y = 6√10
To get x we will use the pythagoras theorem
y² = x²+6²
(6√10)² = x² + 36
360 = x² + 36
x² = 360 - 36
x² = 324
x = 18
Hence x = 18 and y = 6√10
i dont know, sorry...............................................
Hope this helps! Mark brainly please!