Answer:
1. LHJ
2. AB
3. Acute
4. Complement 30, supplement 120
5. AOD
6. 61
7. acute
8. 36
9. Octogon
Step-by-step explanation:
<u><em>Answer</em></u>

<u><em>Explanation</em></u>
Based on the given conditions, formulate:: 
Substitute
into
:: 
Rearrange variables to the left side of the equation: 
Calculate the sum or difference: 
Divide both sides of the equation by the coefficient of variable: 
Cross out the common factor: 
Answer:
Lixin obtains 15 marks
Step-by-step explanation:
Lets write two equations based on the question where: <u>D= Devi and L=Lixin</u>
D=L+15 <em>- "devi scores 15 marks more than lixin"</em>
D=2L <em>- "devi obtains twice as many marks as lexin"</em>
Now, substitute 2L as D in the first equation we wrote: (D=L+15)
2L=L+15
Next, subtract L from both sides:
<u>L=15</u>
1/5 + 1/4.....lowest common denominator is 20
4/20 + 5/20 = 9/20 <==
Answer:
x = 6
Step-by-step explanation:
5x + 15 = 45
Subtract 15 from both sides
5x = 30
Divide by 5 on both sides
x = 6
Hope this helps :)