Dory and Nemo go to Taco Bell for lunch. Dory orders three soft tacos and three double deckers for $11.25. Nemo pays $10.00 for four soft tacos and two Double Deckers. Write a system of equations that represents the lunch orders for Dory and Nemo. Use x to represent soft tacos and y to represent Double Deckers.

X=cost for 1 soft taco

x=cost for 1 doubledecker

dory is

11.25=3x+3y

nemo buys

10=4x+2y

we have

11.25=3x+3y and

10=4x+2y

divide second equation by 2

5=2x+y

multiply by - 3

-15=-6x-3y

add to first equatin

-15=-6x-3y

11.25=3x+3y+

-3.75=-3x+0y

-3.75=-3x

divide both sides by - 3

1.25=x

subsitute

5=2x+y

5=2 (1.25) + y

5=2.5+y

minus 2.5

2.5=y

double dekesr cost $2.50

soft tacos cost $1.25