John has 30 friends. Then amount of male friends is 4 more than the number of female friends. Which system can be used to find the number of male and female friends?

The required system of equations is:

Step-by-step explanation:

First of all, the variables have to be selected to represent the quantities.

Let m be the number of male friends and let f be the number of female friends.

Then according to first statement "John has 30 friends"

And according to second statement "amount of male friends is 4 more than the number of female friends."

Hence the required system of equations is:

step-by-step explanation:

this can be solved first with pythagorean theorem, which tells us to square both legs of the triangle and sum it. this will be equal to the square of the hypotenuse.

the hypotenuse is the side "opposite" the 90 degree angle, which is x.

so we can write using pythagorean theorem,

simplifying:

to further simplify this radical, we need to use the property  

thus