Answer:
BC ≈ 4.0
Step-by-step explanation:
∠ DCA = 180° - 70° = 110° ( adjacent angles )
∠ DAC = 180° - (30 + 110)° ← sum of angles in triangle
∠ DAC = 180° - 140° = 40°
Using the Sine rule in Δ ACD to find common side AC
=
( cross- multiply )
AC × sin40° = 15 × sin30° ( divide both sides by sin40° )
AC =
≈ 11.668
Using the cosine ratio in right triangle ABC
cos70° =
=
=
( multiply both sides by 11.668 )
11.668 × cos70° = BC , then
BC ≈ 4.0 ( to the nearest tenth )
Answer:

Step-by-step explanation:

Move 3k to left hand side and change it's sign
Similarly, move 4.5 to right hand side and change it's sign

Collect like terms

Subtract 4.5 from 18

Divide both sides by 4.5

Calculate

Hope I helped!
Best regards! :D
Answer:
Step-by-step explanation:
The coefficients of x on each side of the equal sign are different, so the equation is <em>not a tautology</em>. It must have exactly one solution.
<span>y=x^2+5x+6
y=4x+12
Solution = (-3,0) and (2,20)
</span><span>y=x^2-3x-1
y=8x-1
Solution = (0,-1) and (11,87)</span>
Answer:
x= -35.153846
Step-by-step explanation:
360=200-5(x+37)
360=195(x+37)
360=195x+7215
360-7215=195x+7215-7215
-6855=195x
-6855/195=195x/195
-35.1538461538=x
-35.153846=x
I THINK ;]