Use the cosine rule.
c=AB=7
b=AC=8
a=BC=3
a^2=b^2+c^2-2bc(cos(A))
=>
cos(A)=(b^2+c^2-a^2)/(2bc)
=(7^2+8^2-3^2)/(2*7*8)
=13/14
=0.9286
Answer:
ef + eg
Step-by-step explanation:
Distributive Property: a(b +c) = (a*b) + (a*c)
e(f +g) = e*f + e*g
= ef + eg
The answer is 12 + 12 = 24
Answer:
Ok:
Step-by-step explanation:
I see that you set up 90 miles = 60 mph * t, where you found out that t = 1.5. What what you needed to do was set 180 miles = 45 mph * t. This is because it is 45 mph for the <em>whole</em> trip. Then, you find that t = 4 hours. That that means that he spent 2.5 hours driving back. Then, we can do d=vt and find 90/2.5 as the speed he went home at. Which comes out to be 36 mph.
