Answer:
-5+(-7)+9+(-3) = -6
Step-by-step explanation:
We need to add the following i.e.
-5+(-7)+9+(-3)
We know that, +(-) = - (minus)
So,
-5-7+9-3 = -12+6
= -6
So, the value of the given expression is equal to -6.
Answer:
x = 35
y = 7
Step-by-step explanation:
See how the image looks like two overlapping triangles. It is given that the triangles are congruent. Its easier to see whats what if you draw the triangles separately. I also flipped over the triangle on the right so they match. Record the given angle measures. Since A is 45° then D is also 45°. DBC is 30°, so we can find the missing angle in triangle DBC. Angles in a triangle add up to 180° so
C + 45 + 30 = 180
C + 75 = 180
C = 105°
This is angle DCB.
Now all the angles are marked. We can set up equations to find x and y. see image.
Answer:
26°
Step-by-step explanation:
AC=tan 64
BC=x=sec 64
Using sine rule
(Sin 64)/tan 64 = (sin BAC)/sec 64
Cos 64 = (sin BAC)(cos 64)
Sin BAC= 1
BAC=90
ACB+ 64+90=180
ACB= 26°
Height of the woman = 5 ft
Rate at which the woman is walking = 7.5 ft/sec
Let us assume the length of the shadow = s
Le us assume the <span>distance of the woman's feet from the base of the streetlight = x
</span>Then
s/5 = (s + x)/12
12s = 5s + 5x
7s = 5x
s = (5/7)x
Now let us differentiate with respect to t
ds/dt = (5/7)(dx/dt)
We already know that dx/dt = 7/2 ft/sec
Then
ds/dt = (5/7) * (7/2)
= (5/2)
= 2.5 ft/sec
From the above deduction, it can be easily concluded that the rate at which the tip of her shadow is moving is 2.5 ft/sec.
