4/3
Remember if two lines are perpendicular, the product of their slopes are -1
From my research, the original system of equations contain the following equations:
<span>2x − y = −4
3x + 5y = 59
where obtained solution is x = 3
Among the choices, it is easier to substitute </span><span>3x + 5y = 59 with one of the choices to see if they yield the same solution set. From trial-and-error, the equation that can replace the original equation is " 13x = 39 ". Among the choices, it is the 4th choice.</span>
So 3 and 1/4 is equal to 4/4+4/4+4/4+1/4=13/4
so she put in 3 and 1/9 or 9/9+9/9+9/9+1/9 or 28/9
28/9+x=13/4
13/4-28/9=x
so we convert so that the bottom numbers are the same
a short cut is 3 and 1/4+x=3 and 1/9
3 1/9+x=3 1/4
subtract 3 from both sides
1/9+x=1/4
subtract 1/4 from both sides
x=1/4-1/9
convert bottom number to same thing
1/9=4/36
1/4=9/36
x=9/36-4/36
x=5/36
5/36 cups
It means you're putting money into your account
