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
Answer:
hopefully tht example will help u
Step-by-step explanation:
To change 0.0002 to scientific notation, move the decimal to the right 4 places so that you get 2. The exponent on the base 10 will be -4 because the decimal was moved to the right 4 places. So 0.0002 in scientific notation is 2×10−4.
Answer:
28 sqr feet.
Step-by-step explanation:
Congruent means equal to. So Cold = Warm for some given property (Area in this case).
28 ft^2 is the answer
Answer: 30
Step-by-step explanation:
40 + 8x = 280
-40 -40
8x = 240
___ ____
8 8
X = 30