The main formula of a spherical surface area is SA= 4 x Pi x r²
the circumference is C= 19cm =2 Pi r, so r = C/ 2Pi = 19 / 6.28 =3.02cm
so the surface area can be found by computing
SA= 4x 3.14x 3.02² =114.5, the nearest square centimeter is <span>A) 114 cm^2</span>
I am going to explain this using the substitution method, considering it appears to be the best in this situation.
We know (from the bottom equation) that y can equal 3x+20. Using this knowledge, we substitute the y in the top equation for 3x+20. Now, we have an equation that looks like this:
3x+20=x^2+2x
Now we need to move x to one side and then do some radicals (square roots).
Subtract the 2x on the right (since it is smaller, negatives = NONONO), which will give you
x+20=x^2
Now, we take the square root of both sides to get
rad(x+20)=x
Now we have to simplify. 20 doesn't have a square root, but 4 goes into 20, and 4 has a square root of 2. This now becomes
2rad(x+5)
This doesn't simplify any further... we have a problem... no way to isolate x as far as my knowledge goes... Sorry, can't help you any further than that, but another person or your teacher might be able to. R.I.P...
Answer:
Step-by-step explanation:
5^2x=7^x+1 ⇔ ln5^2x = ln7^x+1 ⇔ 2xln5 = (x+1)ln7 ⇔ (2ln5-ln7)x = ln7
⇔ x = ln7/(2ln5-ln7)
Answer:
x=10,−10
simple, it could be negative OR positive :D
