Answer:
a) 84π b) 109.2π
Step-by-step explanation:
The formula to find this is v=πr^2h/3
r=d/2. so the radius (r) is 6 because you have to divide the diameter (12) by 2. and the height is 7. so, 6^2=36 and 36x7=252.
252/3=84
and because the question is asking for the EXACT value, you need to just put the pi symbol next to it. Final answer for a is 84π
B) you need to find 30% of 84, which is 25.2 and add it to 84, and you will get 109.2! Final answer is 109.2π.
<span>x-y=2y -> x=3y and
3x-40+2y=180 --> 9y-40+2y=180 --> 11y=220 --> y=20, x=60 --> <A=<C=140 degrees, <B=<D=40 degrees.</span>
Answer:
C
Step-by-step explanation:
In this technique, if we have to factorise an expression like ax2+bx+c, we need to think of 2 numbers such that:
N1⋅N2=a⋅c=1⋅−12=−12
AND
N1+N2=b=−1
After trying out a few numbers we get N1=3 and N2=−4
3⋅−4=−12, and 3+(−4)=−1
x2−x−12=x2−4x+3x−12
x(x−4)+3(x−4)=0
(x+3)(x−4)=0
Now we equate the factors to zero.
x+3=0,x=−3
x−4=0,x=4
Answer:
Lots of steps and answers. Look at the picture.
Step-by-step explanation: