Answer:
C) 5x - 18 = 7
Step-by-step explanation:
Plug in 5 for x.
5x - 18 = 7
5(5) - 18 = 7
Simplify. First, multiply, then subtract.
25 - 18 = 7
7 = 7 (True)
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Answer:Mark Is 9 years old; Christine is 5 years old
Step-by-step explanation:
Present age
LET mark age be x
Christine be x-4 yrs
In 3 yrs Time
Mark will be x+3 yrs old
Christine will be (x -4 +3) = x-1 years old
Also, In 3 years time
Christine = 2/3 Mark
such that
x-1 = 2/3(x+3)
x -1= 2x+6 / 3
3x -3= 2x+6
3X--2X = 6+3
=X=9
Mark Is 9 years old
Christine is x -4 = 9-4=5 years old
Answer: 
Step-by-step explanation:
GCF = Greatest common factor.
For example: 6 is the GCF of 12 and 18.
The given expression: 
It can be written as

Taking out common factor
, we get
![5y(x^2-6xy-7y^2)\\\\ =5y(x^2+xy-7xy-7y^2)\ \ [\because-6xy=xy-7xy]\\\\=5y(x(x+y)-7y(x+y))\\\\= 5y((x+y)(x-7y))\\\\=5y(x+y)(x-7y)](https://tex.z-dn.net/?f=5y%28x%5E2-6xy-7y%5E2%29%5C%5C%5C%5C%20%3D5y%28x%5E2%2Bxy-7xy-7y%5E2%29%5C%20%20%5C%20%5B%5Cbecause-6xy%3Dxy-7xy%5D%5C%5C%5C%5C%3D5y%28x%28x%2By%29-7y%28x%2By%29%29%5C%5C%5C%5C%3D%205y%28%28x%2By%29%28x-7y%29%29%5C%5C%5C%5C%3D5y%28x%2By%29%28x-7y%29)
Hence, 
Answer:
<em>∠B is the largest interior angle of the triangle, and AC is the</em><em> largest</em><em> side.</em>
Step-by-step explanation:
Relationship of sides to interior angles in a triangle-
- The shortest side of a triangle is always opposite to the smallest interior angle.
- The longest side of a triangle is always opposite to the largest interior angle.
So converse of the second property is the side opposite to the largest interior angle is always the largest side.
As ∠B is the largest interior angle of the triangle, so its opposite side which is AC will be the largest side.