Answer:
BC ≈ 14.7 m
Step-by-step explanation:
Using the Sine rule in Δ ABC
=
To find ∠ A subtract the 2 given angles from 180°
∠ A = 180° - (90 + 28)° = 180° - 118° = 62°
Then
=
( cross- multiply )
BC × sin28° = 7.8 × sin62° ( divide both sides by sin28° )
BC = ≈ 14.7 m ( to 3 significant figures )
Answer:
Step-by-step explanation:
The simplified expression is ...
3x(x -12x) +3x² -2(x -2)²
= 3x(-11x) +3x² -2(x² -4x +4) . . . . . simplify contents of parentheses
= -33x² +3x² -2x² +8x -8 . . . . . . . .eliminate parentheses
= (-33 +3 -2)x² +8x -8 . . . . . . . . . . group the coefficients of like terms
= -32x² +8x -8
