It has to be C- addition and subtraction signs.
ANSWER: The number is 10.
Hope this helps!!
I used the variable n as the number we needed to find. The equation was n + 8 + 12 = 3n
The fraction of the total number of marbles is left in the bag after removing and giving part to her friend is 3/8
<h3>Fraction</h3>
let
- Number of marbles in her bag = x
- Number of marbles removed from her bag = 1/2x
Remaining marbles = x - 1/2x
= (2x-x) / 2
= x/2
= 1/2x
Number of marbles given to her friend = 1/4 of 1/2x
= 1/4 × 1/2x
= 1/8x
Number of marbles left in the bag = Remaining marbles - Number of marbles given to her friend
= 1/2x - 1/8x
= (4x-x) / 8
= 3x/8
= 3/8x
Learn more about fraction:
brainly.com/question/11562149
#SPJ1
Answer:
25. 
26. 
Step-by-step explanation:
For 25:
(area of a trapezoid)
(substitute terms)
(collect like terms)
(reduce the fraction by crossing out 2)
(calculate)
For 26:
(equation of area of a circle)
(enter the radius)
(communtative property to reorder the terms)
