-20=-4x-6x
4x+6x=20
10x=20
x=20:10
x=2
proof:
-20=-4×2-6×2
-20=-8-12
(-8)+(-12)=-20
First find out how much one onion weighs so divide 0.75 by 3. This gets you 0.25. Now all you need to do is multiply the weight of one onion by 10, 0.25 x 10 = 2.5
Answer:

Step-by-step explanation:
<u><em>The complete question is</em></u>
A chef bought $17.01 worth of ribs and chicken. Ribs cost 1.89 per pound and chicken costs 0.90 per pound. The equation 0.90 +1.89r = 17.01 represents the relationship between the quantities in this situation.
Show that each of the following equations is equivalent to 0.9c + 1.89r = 17.01.
Then, explain when it might be helpful to write the equation in these forms.
a. c=18.9-2.1r. b. r= -10÷2c+9
we have that
The linear equation in standard form is

where
c is the pounds of chicken
r is the pounds of ribs
step 1
Solve the equation for c
That means ----> isolate the variable c
Subtract 1.89r both sides

Divide by 0.90 both sides

Simplify

step 2
Solve the equation for r
That means ----> isolate the variable r
Subtract 0.90c both sides

Divide by 1.89 both sides

Simplify

therefore
The equation
is equivalent
The equation is helpful, because if I want to know the number of pounds of chicken, I just need to substitute the number of pounds of ribs in the equation to get the result.