Which of the following is a complex number

B

Step-by-step explanation:

A complex number is a number that can be expressed in the form a + bi

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