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

$0.90c+1.89r=17.01$

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

$0.90c=17.01-1.89r$

Divide by 0.90 both sides

$c=(17.01-1.89r)/0.90$

Simplify

$c=18.90-2.1r$

step 2

Solve the equation for r

That means ----> isolate the variable r

Subtract 0.90c both sides

$1.89r=17.01-0.90c$

Divide by 1.89 both sides

$r=(17.01-0.90c)/1.89$

Simplify

$r=9-0.48c$

therefore

The equation $c=18.90-2.1r$ 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.

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3 years ago