3.2d - 4d = 2.3d + 3...simplify by combining like terms
-0.8d = 2.3d + 3....subtract 2.3d from both sides
-0.8d - 2.3d = 3 ...simplify again
-3.1d = 3...divide both sides by -3.1
d = 3/ -3.1
d = - 0.97

or
3.2d - 4d = 2.3d + 3....multiply the equation by 10, gets rid of the decimals
32d - 40d = 23d + 30....subtract 23d from both sides
32d - 40d - 23d = 30....simplify
-31d = 30...divide by -31
d = -30/31
d = - 0.97

5 0

3 years ago

What is the solution to the system of equations?

Dovator [93]

Answer:

Step-by-step explanation:

$\left\{\begin{array}{ccc}x+3y+2z=8&(1)\\3x+y+3z=-10&(2)\\-2x-2y-z=10&(3)\end{array}\right\qquad\text{subtract both sides of the equations (1) from (2)}\\\\\underline{-\left\{\begin{array}{ccc}3x+y+3z=-10\\x+3y+2z=8\end{array}\right }\\.\qquad2x-2y+z=-18\qquad(4)\qquad\text{add both sides of the equations (3) and (4)}\\\\\underline{+\left\{\begin{array}{ccc}-2x-2y-z=10\\2x-2y+z=-18\end{array}\right}\\.\qquad-4y=-8\qquad\text{divide both sides by (-4)}\\.\qquad\qquad y=2\qquad\text{put the value of y to (1) and (3)}$

$\left\{\begin{array}{ccc}x+3(2)+2z=8\\-2x-2(2)-z=10\end{array}\right\\\left\{\begin{array}{ccc}x+6+2z=8&\text{subtract 6 from both sides}\\-2x-4-z=10&\text{add 4 to both sides}\end{array}\right\\\left\{\begin{array}{ccc}x+2z=2&\text{multiply both sides by 2}\\-2x-z=14\end{array}\right\\\underline{+\left\{\begin{array}{ccc}2x+4z=4\\-2x-z=14\end{array}\right}\qquad\text{add both sides of the equations}\\.\qquad\qquad3z=18\qquad\text{divide both sides by 3}\\.\qquad\qquad z=6\qquad\text{put the value of z to the first equation}$

$x+2(6)=2\\x+12=2\qquad\text{subtract 10 from both sides}\\x=-10$

4 0

3 years ago

There were 350 members in the high school marching band last year. This year, the number of marching band members increased by 5

Rudiy27

Answer:

The percentage of the number of marching band members increased by 16% this year.

Step-by-step explanation:

$\frac{56}{350}$ x 100% = 16%

56 is 16% of 350

3 0

3 years ago

Read 2 more answers

Is the following relation a function? (4,2), (1,1), (0,0), (1, -1), (4, -2). Give the domain and range.

Vlada [557]

(x,y)
to be a function
for every x, ther must be only 1 y to corespond to it
basically, x must NEVER repeat with a different y
list them

ah, we see (1,1) an d(1,-1)
also (4,2) and (4,-2)
double offense
1 repeats with 1 and -1
4 repeats with 2 and -2

not a function

domain is all x values
range is all y values
if they repeat, don't list them

domain=(0,1,4)
range=(-2,-1,0,1,2)

8 0

3 years ago