c+3t=48

solve for c in the 2nd equation and you get: c=48-3t. then plug that into the 1st equation for c.

3c+2t=67

3(48-3t) + 2t =67

144-9t+2t=67

-7t=-77

t=11

then plug in that value for t into the previous equation where you solved for c..

c=48-3t

c=48-3(11)

c=48-33

c=15

tapes cost 11

cds cost 15

A) you know that

Three CDs and two tapes cost $67

– Let c dollars represent the price of one CD.

One CD and three tapes cost $48

– Let t dollars represent the price of one tape.

So, thats how they came up with 3c+2t=67 and

c+3t=48

b) solve the linear system

There are 3 way that you can do this. The best way is to turn each problem into slope intercept form and then graph it.

Equation 1

Lets pretend that c is x and t is y

3c+2t=67

Add negative 3c to both sides

3c+(-3c)+2t= +(-3c) +67

You get

2t= -3c+67

Divide both side by 2.

2t/2= -3c/2+ 67/2

t= -1.5c + 33.5

Equation 2

Again pretend that c is x and t is y.

Add -c both sides.

c-c+ 3t= (-c)+ 48

You get

3t= -c+ 48

Now dived both sides by 3.

3t/3= -1c/3 +48/3

Which you get

t= -1/3c + 16.

Now graph both equations by using the slope and the y intecept. (In equation 1, the slope is -1.5 also -1.5/1 and the y intercept is 33.5). Equation 2, slope is -1/3 and the y intercept is 16. Then find the point they intercept. I think that point is you answer for c and d. For, C= x point, and t= ypoint.

3 times 15 + 2 times 11 = 67.

therefore, 15 + 3 times 11 = 48.

you should be able to solve the linear equation with this information.

b) 3c + 2t = 67

c + 3t = 48

c = 48 – 3t

3(48 – 3t) + 2t = 67

144 – 9t + 2t = 67

-7t = -77

7t = 77

t = 11

c + 3t = 48

c = 48 – 3t

c = 48 – 3(11)

c = 15

c) $15

d) $11

Cheers!