Masses of precious stones are measured in carats, where 1 carat = 200 milligrams. What is the mass of a 80-dg diamond in carats?

2/5 carats, or 0.4 carats

Step-by-step explanation:

200/80 = 2.5

1/2.5 = 0.4

x = 10.1

step-by-step explanation:

all of the angles of a tirangle add up to 180º

180 - 65 = 115 (since we already know the value of one angle)

(2x + 7) + (8x + 7) = 115

(combins like terms) 10x + 14 = 115

(isolate the variable subtract 14 from both sides): 10x = 101

(find the variable divide both sides by 10): x = 101/10

x = 10.1