Let's simplify step-by-step To understand :)
3x2−7x−(x2+3x−9)
Distribute the Negative Sign:
=3x2−7x+−1(x2+3x−9)
=3x2+−7x+−1x2+−1(3x)+(−1)(−9)
=3x2+−7x+−x2+−3x+9
Combine Like Terms:)
=3x2+−7x+−x2+−3x+9
=(3x2+−x2)+(−7x+−3x)+(9)
=2x2+−10x+9
Answer :)
=2x2−10x+9
HOPE THIS HELPS
Answer:
Since pair of opposite sides are parallel and adjacent sides meets at right angles, the quadrilateral COAT is a rectangle.
Step-by-step explanation:
The vertices of the given quadrilateral is 
It is sufficient to show that pair of opposite sides are parallel and adjacent sides are perpendicular.
The slope of each side can be found using the formula;

Slope of CO,

A line with a zero slope is a horizontal line.
The slope of OA,

This slope is undefined.
A line with an undefined slope is a vertical line.
This shows that,the side CO and OA of the quadrilateral meets at right angle.
The slope of AT,

This is also a horizontal line.
The slope of TC,

This also a vertical line.
This implies that, side TC and side AT meets at Tat right angles and TC is parallel to OA.
Also AT is parallel to TO.
This shows that COAT is a rectangle.
Answer:
b =21
Step-by-step explanation:
Since this is a right triangle, we can use the Pythagorean theorem
a^2 + b^2 = c^2 where a and b are the legs and c is the hypotenuse
20^2 + b^2 = 29^1
400 + b^2 =841
Subtract 400 from each side
b^2 = 441
Take the square root of each side
sqrt(b^2) = sqrt(441)
b =21
Answer:
b
Step-by-step explanation: