Simplify the following expression. 5.3x − 8.14 + 3.6x + 9.8

A.
-2.84x − 1.66
B.
8.9x + 17.94
C.
-2.84x + 17.94
D.
8.9x + 1.66

D

Step-by-step explanation:

5.3x − 8.14 + 3.6x + 9.8

group the numbers on one side and the x's on the other

5.3x + 3.6x - 8.14 + 9.8

solve

8.9x +  1.66

(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