Question

Mira picked two numbers from a bowl. The difference of the two numbers was 4, and the sum of one-half of each number was 18. The system that represents Mira’s number is below. x-y=4 1/2x+1/2y=18. Which two numbers did Mira pick?

Answer 1

This question give simultaneous equations

x - y = 4 ------------------ (i)

1/2x+1/2y = 18 -------- (ii)

We can solve this problem using the method of elimination (or any other method used in solving simultaneous equations)

Multiply (ii) by 2

x + y = 36  -------- (iii)

add (i)  to (iii)

x - y = 4 ------------------ (i)
x + y = 36  ------------ (iii)
_____________________
2x    = 40

x = 20

x - y = 4

20 - y = 4

y = 16


Mira picked 16 and 20

Answer 2

the answer for edgenuity is option 3, (20, 16)