Answer:
6
Step-by-step explanation:
4(6) - 7y = -18
24 - 7y = -18
-7y= -42
y= 6
To answer this question you have to create a system of equations. The first equation will be that Devi's money (x) equals her brother's money (y), or x = y. The next equation would be that (3/5)x + (7/10)y = 78. You than can substitute x in for y because x = y. The equation would know be (3/5)x + (7/10)x = 78. You then combine the like terms to create an equation of (13/10)x = 78. Then, multiply both sides by 10 / 13 in order to isolate x. This will create the equation x = 60. This means that Devi and her brother each had 60 dollars. You then find out how much they spent and add it together. You can do so with the equation (2/5)x + (3/10)y = z, with z being total money spent. You substitute 60 in for x and for y then solve. When you solve you see that 24 + 18 = z, or that z equals 42. In other words, they spent 42 dollars altogether.
Answer:
X = -3
Step-by-step explanation:
X/2-5 = 1
X/-3 = 1
Multiply both sides by -3 to isolate x
X = -3
Your octagon has a central angle of 360 deg. Since you're speaking of an octagon, which implies that the octagon is made up of eight triangles, divide 360 deg by 8 to obtain the measure of each minor arc formed.
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°
