Someone please help me

We can write 7 + 2 + 1 in two different ways.

a)

b)

Step-by-step explanation:

The commutative property of addition states that we can add the numbers in any order and get the same answer.

For example, if we add 'a' and 'b' together, the commutative property of addition states that we would get the same answer whether we add a + b or b+a.

In other words,

a + b = b + 1

In our case, we are given

7 + 2 + 1

According to the commutative property of addition, we can add the number in any order and get the same answer.

Therefore, we can write 7 + 2 + 1 in two different ways.

a)

b)

Verification:

Thus, the answer will remain the same in any order.

i.e.

7 + 2 + 1 = 7 + 1 + 2 = 1 + 7 + 2

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

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.