Hi!
<u>Given these two equations:</u>
We want to solve using the substitution method. Knowing that x is equal to y + 8, we can simply plug in 'y + 8' in for x in the second equation, like so:
Combine like terms on both sides:
Subtract y from both sides:
Subtract 8 from both sides:
Now, we can simply plug the y value in to the first equation, and solve for x:
Simplify:
<u>Learn more about the substitution (and also elimination!) method here:</u>
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.