Answer:
3x = 4-x "hope this helps"
Step-by-step explanation:
We have to know the angle that is not labelled. (lets call it y)
9x + y= 180
and the sum of the angles of a triangle is 180
5x + (9+x) + y=180
2 simultaneous equations
Answer:
(-4, -8)
Step-by-step explanation:
Use the substitution method. x = -4, so y = (1/2)x - 6 becomes:
y = (1/2)(-4) - 6, or y = -2 - 6, or y = -8.
The solution is (-4, -8).
<span>exact value of sin 157.5 without using a calculator
sin(157.5)=sin(315/2)
Identity: sin(x/2)=±√[(1-cosx)/2]
select positive identity since 175 is in the 2nd quadrant where sin>0
sin(315/2)=√[(1-cos315)/2]
cos 315=cos45 in quadrant IV=√2/2
sin(315/2)=√[(1-√2/2)/2]=√[(2-√2)/4]=√(2-√2)/2
sin(157.5)=√(2-√2)/2
check using calculator:
sin157.5º≈0.382...
√(2-√2)/2≈0.382...</span>
Check the picture below.
make sure your calculator is in Degree mode.
