Answer:
x=14/5
Step-by-step explanation:
Group like terms
2x+8x+7=35
Add similar elements: 2x+8x=10x
10x+7=35
Subtract 7 from both sides:
10x+7−7=35−7
Simplify
10x=28
Divide both sides by 10
10x/10 =28/10
Simplify:
x=14/5
Answer:
10.5
Step-by-step explanation:
2⅝×4=10.5
..............
Answer:

Step-by-step explanation:
Since angle RTS is a right angle, we have three similar triangles.
Thus, 
Cross Products, 
Take the square root: 
Step-by-step explanation:
your teacher was very nice and warned you about the trap in the question.
so, really, what do we have to do ?
a full circle represents 360°.
the shaded sector is the full circle minus the white sector !
this is the same as directly calculating the shaded sector for 360-75 = 285°.
so, the area of a circle is
pi×r²
in our case
pi×20² = 400pi
the needed fraction of the whole circle is either
75/360, if we want to subtract it for the solution
or
285/360, if we want to calculate the solution directly.
both lead to the same result.
400pi×360/360 - 400pi×75/360 =
= 400pi × 285/360 = 10pi × 285/9 = 2850pi/9 =
= 316.6666666...pi ≈ 316.7pi