2x^2-7=4
subtract 4 from both sdies
2x^2-11=0
therefor
2x^2=11
divide by 2
x^2=5.5
square root both sdies
x=-2.345 or 2.345
Answer:
b. DAC≅DBC
Step-by-step explanation:
∠DCB≅∠DCA=90° as they are right angles at the perpendicular lines
DC=DC reflexive property(they are the same line)
AC=CB they are both the radius of the same circle
DAC≅DBC due to SAS(Side angle Side)
The total length of the circle is calculated by the following formula:
Lenght = 2.π.r
As r = 4c
Then,
Lenght = 2.π.4
Lenght = 8π centimetrs
Now use the rule of 3
But we have to know:
...<..> ...
Then,
8π ________ 2π <= 360°
x ________ 3π
2π . x = 8π . 3π
x = (8π . 3π) / 2π
x = (8 . 3π)/ 2
x = 12π centimenters
x ~ 37,69 c
The nearest tenth means 1 decimal place.
so the answer is 8.5
