Answer: d=$12, b=$1
d represents DVDs
b represets books
Step-by-step explanation:
Whenever you have 2 examples of 2 different things (such as books and dvds), make a systems of equations.
Step 1: Write a system of equations
3d+4b= 40
d+6b= 18
Step 2: Eliminate any letter. I'll just choose d.
To elimiate d, you have to make them both equal to the biggest d variable. In other words, make both d terms equal to 3d. To do this, miultiply the 2nd equation by 3, and keep the 1st one the same.
3d+4b=40
3d+18b= 54
Now, elimiate d, by doing 3d-3d= 0. Now use subtraction to solve for b since we used this to get 3 and 3 to 0.
4b-18b=40-54
-14b= -14
b= -14÷-14
b= 1
Each book costs 1 dollar.
Step 3: Plug in b=1 to find how much each dvd costs (plug into any equation)
3d+4b=40
3d+4(1)=40
3d+4=40
3d=40-4
3d=36
d=36÷3
d=12
Each dvd is $12
Step 4: Checks--plug d=12 and b=1 into any equation
3d+4b=40
3(12)+4(1)=40
36+4=40
40=40
It's correct ✅
Also i know this was answered really late but id appreciate if i could get brainliest as i worked pretty hard for this :) Hope i could help the best i could :D
