Answer:
-a + 40 = 28, a = 12
Step-by-step explanation:
If he takes the opposite of his age, that means the current number is negative. We can get -a + 40 = 28, we can then simplify by subtracting both sides by 40 and getting -a = -12 which is equal to a = 12
120000gallons
÷ 10min=12000 min
$24.50
9.10/2=4.55
4.55+19.95=24.50
I hope I helped you^_^
Just multiply the fraction with 100.