Evaluate -x-4y when x= -7&y=5

a) 7x=7

step-by-step explanation:

i believe your answer is 99.7% of 7-year-old children are between 46.6 inches and 49.5 inches tall.

x=-7

step-by-step explanation:

x+3=-10

-10+3=-7

x=-7

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.