I believe it’s 3
I think that because you would do this
1-(-5)
———
5-3
Which would equal 3
The answer is a scalene triangle
Answer: x = 7 (choice C)
"sum of 1 and 3 times a number" means we have the expression 1+3*x for some unknown number x. This is set equal to 22, and we isolate x. The idea is to follow the order of operations PEMDAS in reverse. So start with subtraction and try to undo it. If it's not present, then undo addition, and so on, until x is all by itself on one side.
1+3x = 22
3x+1 = 22
3x+1-1 = 22-1 ... see note 1 below
3x = 21
3x/3 = 21/3 .... see note 2 below
x = 7
note1: Undoing addition. We undo the "+1" by subtracting 1 from both sides
note2: Undoing multiplication. 3x means "3 times x". The inverse of this is division which means we divide both sides by 3
90 and 92.
The whole number below 91 is 90, and the whole number above 91 is 92.
The sum formula for a geometric sequaence is:
sum(n) = a1(1-r^n)/1-r
Where n is the number of terms, a1 is the first term and r is the common ratio:
s(8) = 3(1-1/2^8) / (1-1/2)
s(8) = 3(1-1/256) / 1/2
s(8) = 2 253/256 / 1/2
s(8) = 765/128
The answer is C.
