At Michael’s school, 38% of the students have a pet dog and 24% of the students have a pet cat. Michael found that 11% of the students had both a pet dog and a pet cat. What is the probability that a randomly chosen student at Michael’s school will have a pet dog or a pet cat?

A.
51%
B.
83%
C.
40%
D.
62%

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

or

step-by-step explanation:

we need to solve for 'x' the following equation:  

we have that:

⇒

⇒ ⇒

factorizing, we get that:

  ⇒

then, the solutions are: or

nothing extraneous has been found!

the answer is b.

step-by-step explanation: