Trig law of cosines

determine the approximate measure of angle c.

90.0 degrees

95.7 degrees

60.9 degrees

102.3 degrees

C ≈ 95.7°

Step-by-step explanation:

Law of cosines:

c² = a² + b² − 2ab cos C

where a, b, and c are the sides of the triangle, and C is the angle opposite of side c.

9² = 5² + 7² − 2(5)(7) cos C

81 = 25 + 49 − 70 cos C

81 = 25 + 49 − 70 cos C

7 = -70 cos C

-1/10 = cos C

C ≈ 95.7°

37/3

step-by-step explanation:

step 1: simplify both sides of the equation.

7x+8(x+

1

4

)=3(6x−9)−8

7x+(8)(x)+(8)(

1

4

)=(3)(6x)+(3)(−9)+−8(distribute)

7x+8x+2=18x+−27+−8

(7x+8x)+(2)=(18x)+(−27+−8)(combine like terms)

15x+2=18x+−35

15x+2=18x−35

tep 2: subtract 18x from both sides.

15x+2−18x=18x−35−18x

−3x+2=−35

step 3: subtract 2 from both sides.

−3x+2−2=−35−2

−3x=−37

step 4: divide both sides by -3.

−3x

−3

=

−37

−3

x=

37

3