Answer:
18
Step-by-step explanation:
Note that 75% = 75/100 = 3/4, so 3/4 of the marbles must be blue. Let x be amount of blue marbles added. We can write an equation using this.
75% = 3/4 = (3 + x blue marbles)/(3 + 4 + 3 + x total marbles) = (3+x)/(10+x)
Multiplying by 4(10 + x) on both sides:
3(10 + x) = 4(3+x)
30 + 3x = 12 + 4x
18 = x
Therefore, we must add 18 blue marbles for 75% of the marbles to be blue.
I hope this helps! :)
I think that's 2x but I'm not really sure.
I hope this helps.
Step-by-step explanation:
a+b+c=78
b=10+a
c=2b
then, we back the first
a+10+a+2b=78
2a+2b=78- 10
2a+2(10+a)=68
2a+2a=48
4a=48
a=12
b=22
c=44
length of the slide is lets say 'l' the height (h) opposite to the angle 28 is found by h=l*sin28 where sin28=0.47 approximately h=4.5*0.47 h=2.115m
Answer:
A =
m²
Step-by-step explanation:
Given that a square has a perimeter of (2x - 48),
Each side of the perimeter must be:
(because a square has 4 sides)
We need to determine the side of each perimeter:
s =
Factor out 2 from the numerator:
s = 
Then, cancel out 2 and 4 from the fraction, leaving 2 in the denominator:
s =
← <em><u>This represents the side of a square</u></em>
Therefore, the area of a square is:
A = side (s)²
A =
m²