Michael's lawn mower had 3/8 of a gallon of gasoline in the tank. He started mowing and used all of the gasoline. He put 4/10 of a gallon of gasoline in the tank. After he mowed, 2/4 of a gallon was left in the tank. ​What was the total amount of gasoline Michael used?

11/40 of a gallon

Step-by-step explanation:

The amount of gasoline in the tank of lawn mower = 3/8 of a gallon

Then he put the amount of gasoline in the tank = 4/10 of a gallon

The total amount of gasoline filled in the tank = 3/8 + 4/10

= 3/8 + 2/5

= 15+16/40

= 31/40

The total amount of gasoline filled in the tank = 31/40

The amount of gasoline left in the tank after mowing = 2/4

Total amount of gasoline Michael used = 31/40 - 2/4

= 31-20/40

= 11/40 of a gallon

Alternatively, you can follow this method:

Total amount of gasoline Michael used = 3/8 + (4/10 - 2/4)

= 3/8 + (2/5 - 2/4)

= 3/8 + ( 8-10/20)

= 3/8 + (-2/20)

= 3/8 + (-1/10)

= 3/8 - 1/10

= 30-8/80

= 22/80

= 11/40 of a gallon

Total amount of gasoline Michael used = 11/40 of a gallon

-3

step-by-step explanation:

a drawing really does here:

so i draw the horizontal line y=2 and the vertical line x=-2 at this intersection i put b (this is where my right angle is going to be).   so point b is at (-2,2).   point a is 5 units long and is also on y=2 so this point has to be (3,2) or (-7,2) -doesn't matter i will go with (3,2).

now we know c is at (-2,y) we don't know the y yet bet we know that c is on x=-2.

we have the area of the triangle is .5bh=12.5

we know the base length is 5 (ab)

we have the height is (2-y) if you look at your

plug in

.5(5)(2-y)=12.5

solve for y to get the y-coordinate for c

2.5(2-y)=12.5

divide both sides by 2.5 giving:

2-y=5

now subtract 2 on both sides

-y=3

y=-3

50.6

step-by-step explanation: