John and his friends are going out for pizza for lunch. They split one pizza and 3 drinks. The pizza cost $12.00. They spent a total of $16.95. Find the cost of one large drink.

John and his friends are going out for pizza for lunch. They split one pizza and 3 drinks. The pizza cost $12.00. They spent a total of $16.95. Find the cost of one large drink.

--pizza=P - - - - drinks=D - - - - john and his friends=J--

they split one pizza and 3 drinks ...

(J=P+3D)

the pizza cost $12.00 ...

(P=$12)

since you know the value of P you plug it in ...

(J=$12+3D)

they spent a total of $16.95 ...

J=$16.95

since you know the value of J you plug it in ...

$16.95=$12+3D

and since you have only one unknown variable you can now solve by subtracting $12 on both sides ...

$4.95=3D

then you divide 3 on both sides to keep the variable by itself ...

$1.65=1D

and you end finding the cost of one drink

1D=$1.65 (D=$1.65)