It is one because it is a simplified answer because 9*2= 18 but they got a 9 so that means they dived by 2 so 8*1=8/2=4 so the missing number is 1
Answer:
k= 13
Step-by-step explanation:
Answer:
k = 8
Step-by-step explanation:
We know that 8(10-k) = 2k so:
8(10−k)=2k
<u>Simplify both sides of the equation:</u>
8(10−k)=2k
(8)(10)+(8)(−k)=2k
80+−8k=2k
−8k+80=2k
<u>Subtract 2k from both sides:</u>
−8k+80−2k=2k−2k
−10k+80=0
<u>Subtract 80 from both sides:</u>
−10k+80−80=0−80
−10k=−80
<u>Divide both sides by -10:</u>

k = 8
12+9+15=36 cm. perimeter is basically all the sides added up together