Answer:
Isosceles
Step-by-step explanation:
Answer:
x = 61 degrees
Step-by-step explanation:
The triangle on the right is isosceles and the base angles are congruent
the sum of the inner angles of a triangle is 180 degrees
2 * 74 + y = 180
148 + y = 180
y = 32 degrees
the total angle is 90 degrees
so we have that
90 - 32 = 58 degrees
Also the left triangle is isosceles, so we have
2x + 58 = 180
2x = 122
x = 61 degrees
Answer:
16:12
Step-by-step explanation:
(4+12)=16
16/4 = 4
4x3=12
Another method:
4---------3
16-------x
Cross multiplication
4x=16x3
4x=48
x=12
Answer:
-23x = 7
Step-by-step explanation:
-3x - y =0
×5. ×5 ×5
-15x -5y = 0
-8x +5y = 7
-15x -5y -0
-23x = 7
Answer: Choice A
S9 = (9/2)*(2+26)
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The formula is
Sn = (n/2)*(a1+an)
where
Sn = sum of the first n terms (nth partial sum)
n = number of terms
a1 = first term
an = nth term
In this case,
n = 9
a1 = 2 (plug in n = 1 into the formula an = 3n-1 and simplify)
an = a9 = 26 (plug n = 9 into the formula an = 3n-1 and simplify)
So,
Sn = (n/2)*(a1+an)
S9 = (9/2)*(2+26)
will help us find the sum of the first 9 terms of this arithmetic sequence
