lisa spends 1/4 of her earnings on rent and 1/5 of her earnings on food. let m stand to
monthly earnings in dollars. which of the following expressions represents the number of
dollars lisa has left at the end of the month after paying rent and buying food.

Step-by-step explanation:

Let her total earnings be m

Rent = 1/4m

Food = 1/5m

Amount left = m - 1/4m - 1/5m

Amount left = (20m - 5m - 4m)/20

Amount left = 11m/20

i dont get the question

step-by-step explanation:

system of linear equation

step-by-step explanation:

as given in the data

a= 20 , b= -12

let us suppose that it is a straight line equation

now we know the formula for the system of linear equation

b= ma + c )

here m is slope of a straight line which is equal to formula

m=   (ii)

and here c is a constant

now putting the value of a and b in equation (ii)

m=

m=

putting the value of a,b and m in equation (i) gives us

-12 = + c

-12=-12 + c

adding 12 to both sides

-12 +12 = -12 +12 +c

0 =c

or c=0

as the value of the constant is zero which gives us that it is a linear equation and this order pair satisfies the system of linear equations.