Answer:
$20
Step-by-step explanation:
We are given the percentages of how much she spent on each purchase but we need the percentage of what is left after each purchase. We calculate this by subtracting each percentage from 100% like so.
100% - 40% = 60%
100% - 20% = 80%
100% - 50% = 50%
Next we need to do is change the percentages into decimal format. We do this by moving the decimal 2 digits to the left. Therefore the percentages wasted are the following
60.0% ⇔ 0.60
80.0% ⇔ 0.80
50.0% ⇔ 0.50
Now that we have the percentages in decimal format we can calculate the total price (t) by retracing the spending process. The spending process was following.



So we have to retrace by solving for
, then
, and finally (t)
... divide both sides by 0.50

.... divide both sides by 0.20

.... divide both sides by 0.60
Finally we can see that the Total amount of money that Alice had before lunch was $20
Answer:
Area of the rectangle = 700 - 2w²
Step-by-step explanation:
In the picture attached one side of the rectangle is Barn.
Two perpendicular sides of the barn are width 'w' and one parallel side to the barn is 'l'.
Jamal has the fencing having length = 700 feet
So, to cover three sides of the rectangle length of wire required = (2w + l) feet
This length should be equal to the length of the wire, which is to be used to cover these three sides.
(2w + l) = 700
l = 700 - 2w ------(1)
Area of the rectangle = lw
By replacing the value of l from equation 1
Area = w(700 - 2w)
Area = 700w - 2w²
The perimeter of a triangle is the sum of its side lengths.
The perimeter of the triangle is: 
<u>The sides of the triangle are:</u>
Side 1 = (8d - 3) cm
Side 2 = (6d + 2) cm
Side 3 = (7f + 8) cm
The perimeter (P) is calculated as:
P = Side 1 + Side 2 + Side 3
So, we have:

Remove brackets

Collect like terms


Hence, the perimeter of the triangle is: 
Read more about perimeters at:
brainly.com/question/6465134
<span>Find the area of two sides (Length*Height)*2 sidesFind the area of adjacent sides (Width*Height)*2 sidesFind the area of ends (Length*Width)*2 ends<span>Add the three areas together to find the surface area</span></span>
Answer:
1/8 = 0.125
3/5= 0.60
30%=0.3
0.45=9/20
1.5=150%
Hey try to do these question by your self next time OwO