Answer B is correct. She forgot to use a variable for 1.49. The correct equasion would be:
So hmm notice the picture below
one is 7x5x1.75 the volume of a rectangular prism is V = length * width * height
so 7*5*1.75 gives us 61.25 ft³
the second one, is larger by some width and length we dunno, but we know that it required that 61.25 plus an extra 17.5 to fill it up, so its volume is 61.25 + 17.5 or 78.75
the height is the same... so

so.. if you factor 45, to two factors, one will be the length, the other the width
Your answer is 3/7 because you have to go 5-5=0 and 5/7-2/7=3/7 so it is 3/7
The only error you made is on problem 3. Everything else is correct. Nice work.
-------------------------------------------------------
Here is how to solve problem 3
Plug x = 1 into the equation and solve for y
-3x + y = 1
-3*1 + y = 1 ... replace x with 1
-3 + y = 1
y - 3 = 1
y - 3 + 3 = 1 + 3 .... add 3 to both sides
y = 4
<h3>The answer is 4</h3>
-------------------------------------------------------
Verifying the answer:
Plug (x,y) = (1,4) into the equation. Both sides should be the same number after simplifying both sides.
-3x + y = 1
-3*1 + 4 = 1 ..... replace x with 1; replace y with 4
-3 + 4 = 1
1 = 1
The answer is confirmed.
If you were to graph -3x + y = 1, which is equivalent to y = 3x+1, you'll find that the point (1,4) is on this line.