70-3·6+9
Remember PEMDAS.
You must multiply the 3 and 6 together, and you would get 18.
Then, you subtract 18 from 70, which would give you 52.
And finally, you would add 9 to 52, getting 61 as your final answer.
Answer:
A
Step-by-step explanation:
Given
y - 2x - 8 = 0 ( add 2x + 8 to both sides )
y = 2x + 8 → (1)
y² + 8x = 0 → (2)
Substitute y = 2x + 8 into (2)
(2x + 8)² + 8x = 0 ← expand left side using FOIL and simplify
4x² + 32x + 64 + 8x = 0
4x² + 40x + 64 = 0 ( divide through by 4 )
x² + 10x + 16 = 0 ← in standard form
(x + 8)(x + 2) = 0 ← in factored form
x + 8 = 0 ⇒ x = - 8
x + 2 = 0 ⇒ x = - 2
Substitute these values into (1) for corresponding values of y
x = - 8 : y = 2(- 8) + 8 = - 16 + 8 = - 8 ⇒ P (- 8, - 8)
x = - 2 : y = 2(- 2) + 8 = - 4 + 8 = 4 ⇒ Q (- 2, 4 )
Calculate the length of PQ using the distance formula
PQ = 
with (x₁, y₁ ) = P (- 8, - 8) and (x₂, y₂ ) = Q (- 2, 4 )
PQ = 
= 
= 
= 
= 
= 
=
× 
= 6
→ A
Answer:
15:6:14
Step-by-step explanation:
AB:BD is split into a total of 3+4=7 parts.
AC:CD is split into a total of 3+2=5 parts.
So, if the two ratios are put on a number line together with the points A, B, C, and D, the number line would be split into a total of 35 parts (the LCM of 7 and 5).
AB would be (3/7)*35=15.
CD would be (2/5)*35=14
BC would be 35-(15+14)=6
So, the ratio is 15:6:14.
Using the Law of Sines (sina/A=sinb/B=sincC for any triangle)
sinc/28=sin90/53 (sin90=1) multiply both sides by 28
sinc=28/53 take the inverse of sin (arcsin) of both sides
c=arcsin(28/53)°
c≈31.89° (to nearest hundredth of a degree)
So it is obvious that they rounded to nearest tenth of a degree
c≈31.9°