Answer:
80 hours
Step-by-step explanation:
let d represent doug, let l represent laura
first, set up a system of equations representing the problem:
since doug spent 10 less than twice the hours laura did, and we know that the total amount of hours they spent together is 230:
l=2d+10
d+l=230
then solve:
*first i rearranged the equations so i can solve this system of equations using elimination method*
l-2d=10
l+d=230
*subtract*
3d=240
d=80
so, doug spent 80 hours in the lab
13 is not the same as 1/3! The division symbol is not a symbol used to connect two numbers, it is used to find their quotient. For example, 6/2 would be like saying: You have 6 cookies, and 2 friends. How many cookies does each friend get? The answer is obviously not 62, it is 3! So, the exact quotient is 0.3 repeating. You could memorize this or use the fact that 0.9 repeating is 1.
Answer:
Its the last one I beleive not sure
Step-by-step explanation: