Answer:
a = 5
Step-by-step explanation:
assuming (a-1, 9) is in the form of (x,y):
9(a-1) - 5(9) = -9
9a - 9 - 45 = -9
9a = 45
a = 5
Answer:
60
Step-by-step explanation:
You would just plug everything in so you get -5(-2-(-5)(-2)) which can be reduced so -5(-12) which is 60
Answer:
A
Step-by-step explanation:
Given 2 sides and the included angle use the Cosine rule to solve for x
x² = 1.6² + 1.1² - (2 × 1.6 × 1.1 × cos78° )
= 2.56 + 1.21 - ( 3.52 × cos78° )
= 3.77 - 0.7318
= 3.0382
Take the square root of both sides
x =
= 1.7 → A