Answer:

Step-by-step explanation:
<u><em>The picture of the question in the attached figure</em></u>
we know that
The perimeter of a triangle is the sum of the length of their three sides
so

where
a,b,c are the length sides of the triangle
In this problem we have

substitute and solve for the missing length


now, there are 1000 grams in one Kilogram, so in 1680 grams, there are 1680/1000 Kilograms, namely 1.680.
Answer:
For the first one just multiply all of the three numbers
and the second is the same, just multiply and you'll get your answer.
Step-by-step explanation:
Answer:
x = 112
Step-by-step explanation:
We can create two equations 1. one that calculates calories burned and 2.another that calculates minutes:
20*x + 5*y = 1200
x + y = 120
Then we can solve for x
x = 120 - y
then we can plug that into the top equation:
20(120 - y) + 5y = 1200
divide by 5:
4(120 - y) + y = 240
distribute:
480 - 4y + y = 240
and then do all that combining like factors what not and simplify and solve:
480 - 3y = 240
-3y = -240
y = 8
NOW WE CAN JUST PLUG IN THE ANSWER FOR Y TO FIND X
8+x =120
x = 112