Answer:
r=1
Step-by-step explanation:
-4 r -10r + -5= -19
-4r + (-10r) + -5=-19
-14r+ -5 = -19
-14r + -5 +5= -19+5
-14r= -14
r=1
Answer:
−
48828125
Step-by-step explanation:
you can use a calculator for algebra
c^2 = a^2 + b^2 - 2(ab)(cos C)
c^2 + 2(ab)(cos C) = a^2 + b^2
2(ab)(cos C) = a^2 + b^2 - c^2
cos C = (a^2 + b^2 - c^2) / 2ab - Answer choice E
Hope this helps! :)