Joseph ate 2/5 of a cake while Mary ate 1/4 of the cake. What percent of the cake was left?

35%

Step-by-step explanation:

To solve this, you need to add the total amount of eaten cake and subtract it from the original cake.

So, Joseph ate 2/5, and Mary ate 1/4.

To add, you need to make them a common denominator (bottom number),

so you can multiply the first fraction by 4/1 and the second number by 5/1 in order to get the same denominator, as it readies you up to add.

Now you have 8/5 and 5/4.

The least common denominator is 20, as 5 and 4 is most close to 20 together as factors.

8/20 + 5/20 = 13/20.

Since you are looking for the leftover cake, it would be the remaining cake, so 20/20 - 13/20 = 7/20

You are using percents, so 7/20 becomes 35/100, as 7/20 can be multiplied by 5/5 to get the denominator of 100.

As a percent, it would just be 35.

let's solve your equation step-by-step.

4x+2=2x+12

step 1: subtract 2x from both sides.

4x+2−2x=2x+12−2x

2x+2=12

step 2: subtract 2 from both sides.

2x+2−2=12−2

2x=10

step 3: divide both sides by 2.

2x

2

=

10

2

x=5

step-by-step explanation: