Difference in doughnuts = 50 - 40 = 10
Difference in money = 15 + 5 = 20
20 ÷ 10 = $2
Each doughnut costs $2
<em>Check:</em>
40 x 2 + 5 = $85
50 x 2 -15 = $85
Ravi has $85 at first.
Each doughnut costs $2
X-4=18
X=18+4
X=22
10=M+7
M=10-3
M=3
4X=24
X=24÷4
X=6
-X=9
X=9×-1
X=-9
6M-5=1
6M=1+5
6M=6
M=6÷6
M=1
5A+7=4A
5A-4A=-7
A=-7
N/5=7
N=7×5
N=35
8=1/2X+6
16=X+12
-X=12-16
-X=-4
X=4
You’d set up a proportion. I did 25/15=7x-40/18.
Then you would cross multiply to get 15(7x-40)=450
Distribute the 15.
105x-600=450
Add 600 to both sides, so the -600 cancels out.
Then you’re left with 105x=1050
Divide both sides by 105 and you get x=10