Prove that cos130°+cos110°+cos10°=0

Use the formula cosC+cosD:2cos(C+D/2)cos(C-D/2) Use this in the question: 2cos(10+110/2)cos(10-110/2)+cos130=0 2cos60°cos(-50°)+cos130°=0 2×1/2.cos50+cos130=0 cos50+cos130=0 2cos(50+130/2)cos(50-130/2)=0 2cos90.cos40=0 2×0.cos40=0 0=0 H.P

Step-by-step explanation:

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