Answer:
C. 40-4x-12x^2
Step-by-step explanation:
very simple
? – (20 – 4x – 5x2) = 20 – 7x2, so ? = 20 – 7x2 + (20 – 4x – 5x2)
? = 20 – 7x2 + (20 – 4x – 5x2)=20-7x²+20-4x-5x²=40-12x²-4x
If you work out the constants it says:
25+x²=100
Which simplifies to x=√75 or x=-√75
Answer:
Option 4.∠ERT and ∠MRC
Step-by-step explanation:
Definition of vertical angles : The angles opposite each other when two lines cross. They are always equal.Vertical" refers to the vertex (where they cross).They are also called vertically opposite angles.
Option 1. ∠KRC and ∠CRH
Refer the figure .
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 2. ∠KRE and ∠ERT
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 3. ∠MRC and ∠KRM
These angles does not satisfy the definition of vertical angles . since these angles are not opposite.
Option 4.∠ERT and ∠MRC
MT and EC are the two lines that cross each other at vertex R ,
Thus ∠ERT and ∠MRC are opposite to each other .
Hence ∠ERT and ∠MRC are pair of vertcal angles .
