Evaluate 5x – 2y + (7x – y) for x = 7 and y = –2

90

Step-by-step explanation:

5x – 2y + (7x – y)

Combine like terms

12x -3y

Let x = 7 and y = -2

12(7) -3(-2)

84 +6

90

90

Step-by-step explanation:

Hi there!

We are given this expression:

5x-2y+(7x-y) and we want to evaluate it if x=7 and y=-2

First, let's combine like terms, as that will make it easier for when we substitute the values into the expression

Open up the parentheses

5x-2y+7x-y

Combine like terms

12x-3y

Now substitute 7 as x and -2 as y into the expression

12(7)-3(-2)

Multiply

84+6

Add

90

Hope this helps!

(0,-3) see attached graph

step-by-step explanation:

a. to solve the system, graph the two equations.

x = y+3 becomes y=x-3 has m=1/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move up 1 unit and 1 unit to the right. plot a point and connect.

y=-4x+3 has m =-4/1 and b=-3. start at (0,-3) on the y-axis and plot a point. then move down four units and to the right 1 unit. plot a point and connect.

the solution is the point (x,y) where the two lines intersect. by the graph below it is (0,-3).

b. to solve by substitution, substitute y = -4x-3 into x= y+3

x= (-4x-3) +3

x=-4x

5x=0

x=0

now substitute x = 0 back in to find y.

y= -4(0)-3

y=0-3

y=-3

solution is (0,-3)

c. use elimination by adding the equations together.

x-y=3

4x+y=-3

5x=0

x=0

then substitute into one equation to find y.

y=-4(0)-3

y=-3

a

step-by-step explanation:

the answer is a