Answer:
b
Step-by-step explanation:
it isn't c because theres a theorem that says that opposite angles in a parallelogram are congruent
it isn't d because if the opposite angles are 90 and 90 they are supplementary
a is correct, but for the wrong reason
its b
Answer:
(5x+4)(5x-6)
Step-by-step explanation:

Separate into two parts, first realizing that the only two factor pairs for 25 are 5 and 5 or 1 and 25. Using 5 and 5 makes the most sense, so
(5x )(5x )
The other two numbers need to multiply to -24 and add up to -10.
Pairs that muliply to 24 could be 1 and 24, 2 and 12, 3 and 8, and 4 and 6. The more you factor the easier it will be to quickly discern which numbers to use. In this case, the right pair is 4 and 6. Because it needs to add up to -10, it should be 4 and -6 (because multiplying out, -30 + 20 = -10).
Thus, the final factored equation is (5x+4)(5x-6). You can check this by FOILing and making sure you get the original equation.
When finding the third side of a scalene triangle, use Law of Cosine with its formula
c^2 = A^2+B^2 - 2AB(cosC)
Now, you just have to input all your data in the formula,
c^2 = 6^2+11^2 - 2(6)(11)(cos40degrees)
c^2 = 36+121 - 2(6)(11)(cos40degrees)
c^2 = 36+121 - 2(6)(11)(0.77)
c^2 = 157 - 101.12
c^2 = 55.88
c = square root of 55.88
c = 7.48 ft
Length of EF is 7.48 ft
Answer:
y = x - 1
Step-by-step explanation:
The equation of a line in slope- intercept form is
y = mx + c ( m is the slope and c the y- intercept )
y = - x - 1 ← is in slope- intercept form
with slope m = - 1
Given a line with slope m then the slope of a line perpendicular to it is
= -
= -
= 1, thus
y = x + c ← is the partial equation of the perpendicular line
To find c substitute (- 1, - 2) into the partial equation
- 2 = - 1 + c ⇒ c = - 2 + 1 = - 1
y = x - 1 ← equation of perpendicular line