Answer:
times you have to remove a red marble
Step-by-step explanation:
8 /30/=3.75
=3.75
2x+y=9
3x+5y=19
I will do this problem in 2 ways. I.)Substitution II.)Elimination
Solution I.) Substitution
We can subtract 2x from both sides in the first equation.
y=9-2x
Now we can substitute the y in the second equation with 9-2x
3x+5(9-2x)=19
-7x+45=19
-7x=-26
x=26/7
y=9-2(26/7)=11/7
Solution II.)Elimination
We can multiply both side of first equation by 5 to get a 5y in both equations.
10x+5y=45
Now because both are positive 5y we just need to do simple subtraction of the 2 equation, each side respectively.
(10x+5y)-(3x+5y)=45-19
7x=26
x=26/7
2*26/7+y=9
y=11/7
Ultimately you get the same answer, both are viable methods, some problems are faster with one method but I recommend mastering both since they are very useful.
setup a simple algebraic equation and solve.
5x = 7x-28
-5x -5x
0=2x-28
+28 +28
28=2x
Now divide both sides by 2 and you get that she is 14
Part A
1 day = 1/4 hours of practice
7 days = 7/4 hours of practice (multiply both sides by 7)
1 week = 7/4 hours of practice
1 week = (4+3)/4 hours of practice
1 week = (4+3)/4 hours of practice
1 week = (4/4)+(3/4) hours of practice
1 week = 1+(3/4) hours of practice
1 week = 1 & 3/4 hours of practice
side note: 1 & 3/4 = 1.75
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Part B
Take the result from part A, and multiply it with 60
So we'll have 60 times 1&3/4 on the left side on the first line, then 60*(1+3/4) on the right side of this same line.
The rest of the lines look like this
(60*1) + (60*3/4)
60 + 60*3/4
60 + 180/4
60 + 45
105 minutes
